Control device, cultivation greenhouse, and control method

Abstract

Provided is a control method that makes it possible to control the temperature inside a greenhouse to a temperature suited to the growth of plants while reducing the power consumption required for temperature control. A control device according to the present invention comprises an acquisition unit that acquires the power consumption of an air conditioner that air-conditions the inside of a cultivation greenhouse, an air-conditioning control unit that performs air-conditioning control via the air conditioner such that the temperature around a cultivation shelf that is inside the cultivation greenhouse is a prescribed target temperature, and a determination unit that, when the difference between the power consumption of the air conditioner and a prescribed threshold value is at or below a prescribed value, determines that power consumption peak cut control that reduces the power consumption is to be performed. When the determination unit has determined that the power consumption peak cut control is to be performed and the air-conditioning control unit is to perform control via the air conditioner such that the temperature around the cultivation shelf is the target temperature, the air-conditioning control unit modifies the target temperature in a direction that reduces the load of the air conditioner and performs the air-conditioning control via the air conditioner.

Description

Control Device, Cultivation House, and Control Method

[0001] The present disclosure relates to a control device for a cultivation house, a cultivation house, and a control method. The present disclosure claims priority based on Japanese Patent Application No. 2025-5208 filed in Japan on January 15, 2025, and incorporates its content herein by reference.

[0002] Patent Document 1 discloses a plant cultivation house including an opening / closing 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 / closing of the skylight, the operation of the skylight fan, and the opening / closing of the curtain based on thresholds provided stepwise between the allowable maximum temperature and the minimum temperature. When performing house cultivation, operation within limited costs is required. For example, when cooling the inside of the house in summer, the cost of power consumption required for cooling may increase. Patent Document 1 does not disclose a method for suppressing the power consumption of house cultivation.

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

[0004] There is a need for control that can reduce the power consumption required for temperature control while controlling the temperature inside the house to a temperature suitable for plant growth.

[0005] The present disclosure provides a control device, a cultivation house, and a control method that can solve the above problems.

[0006] According to one aspect of the present disclosure, a control device includes an acquisition unit that acquires the power consumption of an air conditioner that performs air conditioning inside a cultivation house, an air conditioning control unit that performs air conditioning control by the air conditioner so that the temperature around a cultivation shelf in the cultivation house becomes a predetermined target temperature, and a determination unit that determines to perform peak power cut control for reducing power consumption when the difference between the power consumption of the air conditioner and a predetermined threshold value becomes equal to or less than a predetermined value. When the determination unit determines to perform the peak power cut control, the air conditioning control unit changes the target temperature in a direction in which the load of the air conditioner decreases and performs air conditioning control by the air conditioner when controlling so that the temperature around the cultivation shelf becomes the target temperature by the air conditioner.

[0007] According to one aspect of the present disclosure, the cultivation greenhouse comprises a building that houses cultivation shelves, an air conditioner that provides air conditioning for the building, a power monitor that measures the power consumption of the air conditioner, and the control device described above.

[0008] According to one aspect of the present disclosure, the control method includes the steps of: acquiring the power consumption of an air conditioner that provides air conditioning in a cultivation greenhouse; performing air conditioning control by the air conditioner so that the temperature around the cultivation shelves in the cultivation greenhouse reaches a predetermined target temperature; and deciding to perform power consumption peak cut control to reduce power consumption when the difference between the power consumption of the air conditioner and a predetermined threshold falls below a predetermined value. If it is decided in the decision-making step to perform the power consumption peak cut control, then in the step of performing air conditioning control, when the air conditioner controls the temperature around the cultivation shelves to reach the target temperature, the target temperature is changed in a direction that reduces the load on the air conditioner, and air conditioning control is performed by the air conditioner.

[0009] According to the control device, cultivation greenhouse, and control method described above, it is possible to control the temperature inside the greenhouse to a temperature suitable for plant growth while reducing the power consumption required for temperature control.

[0010] This is a front view showing an example of a cultivation greenhouse according to the embodiment. This is a plan view showing an example of a cultivation greenhouse 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 the set temperature of an air conditioner according to the embodiment. This is a diagram illustrating the control of the operating mode of an air conditioner according to the embodiment. This is a diagram illustrating the control of curtains according to the embodiment. This is a diagram illustrating peak cut control of power consumption according to the embodiment. This is a flowchart showing an example of peak cut control of power consumption 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. The acquisition unit 51 acquires measured values ​​measured by power monitor C4. 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). When the temperature inside the cultivation shelf 10 of the air conditioners 30 and 31 approaches the target value, the air conditioning control unit 52 reduces the air conditioning intensity and switches to low-load operation. The curtain control unit 53 controls the opening and closing of 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. When the power consumption of the air conditioners 30 and 31 approaches a threshold, the air conditioning control unit 52 closes curtain 41 to reduce the load on the air conditioners 30 and 31. If the power consumption of the air conditioners 30 and 31 still does not decrease sufficiently, the air conditioning control unit 52 further closes curtain 40 to reduce the load on the air conditioners 30 and 31. The storage 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 thresholds 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 control of the air conditioning command value (set temperature) 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 air conditioner's temperature sensors (temperature sensors C2, C3) and the command value (set temperature) to the air conditioner, 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, thereby adjusting the air conditioning intensity of the air conditioner. If the air conditioners 30 and 31 can receive the cooling intensity as a command value, the cooling intensity calculator 521 may output a value to the air conditioners 30 and 31 as a command. In this case, for example, air conditioner 30 operates with the temperature obtained by adding the temperature measured by temperature sensor C2 to the received cooling intensity as the set temperature.

[0018] Next, we will explain the operation mode control. Figure 5 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 5. The air conditioning control unit 52 determines the operating 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 5). 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 set 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 5). 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 set 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 5). 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 5). 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 5). 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 5).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] (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.

[0020] Figure 6 is a diagram illustrating the control of the curtain according to the embodiment. The curtain control unit 53 is equipped with 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 closing speed (speed at which the curtain closes). Regarding the closing speed of the curtain, 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 opening speed (speed at which the curtain opens). The smaller the (cultivation shelf temperature - target temperature), the faster the value may be output. In order to capture as much sunlight as possible without increasing the 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 opening / closing speed of the curtain. 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 opening / closing direction of the curtain and output a predetermined opening speed (opening speed) of the curtain.

[0021] 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 opening 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).

[0022] (Peak Cut Control of Power Consumption) The control device 50 performs the above-mentioned air conditioning control and curtain control, but especially on hot summer days, the load on the air conditioners 30 and 31 increases, and power consumption may exceed the allowable cost limit for the cultivation greenhouse. Producers must produce plants P within a certain cost range. Therefore, in this embodiment, peak cut control of power consumption is performed to reduce the power cost required for temperature control of the cultivation greenhouse. Figure 7 is a diagram illustrating the peak cut control of power consumption according to the embodiment. In the graph of Figure 7, the vertical axis represents power consumption, and the horizontal axis represents time. L1 shows the change in power measured by the power monitor C4. A threshold Th is set for the total power consumed by the air conditioners 30 and 31. The difference between the threshold Th and the power measured by the power monitor C4 is called the margin α. When the margin α falls below a predetermined value β, the curtain control unit 53 first closes the curtain 41 at a predetermined speed. Even when the curtain 41 is closed, the curtain control unit 53 evaluates the margin α at a predetermined control cycle. For example, the curtain control unit 53 may close the curtain 41 at a predetermined speed, and if the margin α exceeds the predetermined value β during this process, it may stop the operation of the curtain 41 at that opening degree. For example, the curtain control unit 53 may have a function that outputs the opening and closing direction and speed of the curtain when a margin α is input, and may calculate the opening and closing direction and speed of the curtain 41 based on this function, and control the opening and closing operation of the curtain 41 based on the calculated opening and closing direction and speed. When the curtain 41 is closed, light is blocked, which reduces the load on the air conditioners 30 and 31 and reduces the rate of increase in power consumption of the air conditioners 30 and 31 (power gradient mitigation) (L2 in Figure 7).

[0023] If the margin α remains below a predetermined value β even when the curtain 41 is fully closed, the curtain control unit 53 closes the curtain 40. For example, the curtain control unit 53 may close the curtain 40 at a predetermined speed, and when the margin α becomes equal to or greater than the predetermined value β, it may stop the operation of the curtain 40 at that opening. For example, the curtain control unit 53 may input the margin α into the above-mentioned function, calculate the opening and closing direction and speed of the curtain 40, and control the opening and closing operation of the curtain 40 based on the calculated opening and closing direction and speed. Closing the curtain 40 further blocks the amount of light reduced by the curtain 41, thereby reducing the load on the air conditioners 30 and 31 and reducing the power consumption of the air conditioners 30 and 31.

[0024] If the margin remains below a predetermined value even when curtains 41 and 40 are fully closed, the air conditioning control unit 52 raises the target temperature of the cultivation shelf 10 for a short time. The duration and extent of the target temperature increase are set arbitrarily within a range that minimizes the impact on plant P growth. For example, the duration of the target temperature increase is 1 to several hours, and the temperature increase is 2 to 3 degrees. The target temperature increase can be achieved by raising the target temperature of the cultivation shelf 10, or by increasing the command value (set temperature) calculated from the cooling intensity output by the cooling intensity calculator 521. By raising the target temperature of the air conditioners 30 and 31, the power consumption of the air conditioners 30 and 31 can be reduced.

[0025] (Operation) Next, with reference to Figure 8, the peak cut control of power consumption will be described. Figure 8 is a flowchart showing an example of peak cut control of power consumption according to the embodiment. The acquisition unit 51 acquires power consumption from the power monitor C4 (step S11). The acquisition unit 51 outputs the acquired power consumption to the curtain control unit 53.

[0026] Next, the curtain control unit 53 calculates a power margin α by subtracting the power consumption obtained in step S11 from a power consumption threshold Th. The curtain control unit 53 determines whether the calculated margin α is less than or equal to a predetermined value β (step S12). If the margin α exceeds the predetermined value β (step S12; No), the process from step S11 is repeated. If the margin α is less than or equal to the predetermined value β (step S12; Yes), the curtain control unit 53 closes the first curtain 41 according to the margin α (step S13). For example, the curtain control unit 53 gradually closes the curtain 41 at a predetermined speed. The curtain control unit 53 repeats the same process as in steps S11 and S12 while gradually closing the curtain 41. If the margin α exceeds the predetermined value β, the curtain control unit 53 may stop opening and closing the curtain 41 at that opening, and then resume closing the curtain 41 when the margin α becomes less than or equal to the predetermined value β again. Alternatively, the curtain control unit 53 may continue closing the curtain 41 until the curtain 41 is fully closed, regardless of the margin α.

[0027] When curtain 41 is fully closed (step S14; Yes), curtain control unit 53 acquires the power consumption measured by power monitor C4 through acquisition unit 51 (step S15) and determines whether the margin α is less than or equal to a predetermined value β (step S16). If margin α exceeds the predetermined value β (step S16; No), the process from step S15 is repeated. If margin α is less than or equal to the predetermined value β (step S16; Yes), curtain control unit 53 closes the second curtain 40 according to the margin α (step S17). For example, curtain control unit 53 gradually closes curtain 40 at a predetermined speed. Curtain control unit 53 repeats the same process as in steps S15 and S16 while gradually closing curtain 40. Curtain control unit 53 may stop opening and closing curtain 40 at its current opening degree when margin α exceeds the predetermined value β, and then resume closing curtain 40 when margin α becomes less than or equal to the predetermined value β again. Alternatively, the curtain control unit 53 may continue closing the curtain 40 until the curtain 40 is fully closed, regardless of the margin α.

[0028] When curtain 40 is fully closed (step S18; Yes), curtain control unit 53 notifies air conditioning control unit 52 that curtains 41 and 40 are fully closed. The air conditioning control unit 52 then acquires the power consumption measured by power monitor C4 through acquisition unit 51 (step S19) and determines whether the margin α is less than or equal to a predetermined value β (step S20). If margin α exceeds the predetermined value β (step S20; No), the process from step S19 is repeated. If margin α is less than or equal to the predetermined value β (step S20; Yes), the air conditioning control unit 52 raises the target temperature (step S21). For example, the air conditioning control unit 52 raises the target temperature of the cultivation shelf 10 by a few degrees for a predetermined time. After the predetermined time has elapsed, the air conditioning control unit 52 returns the target temperature of the cultivation shelf 10 to its original value and executes the air conditioning control described with reference to Figure 4. If the margin α remains below a predetermined value β even after operating with the target temperature increased for a predetermined period of time, the air conditioning control unit 52 may continue operating with the target temperature increased to the extent that it does not affect the growth of the plants P. Alternatively, the system may return to the normal air conditioning control described with reference to Figure 4, continue the normal air conditioning control for a certain period of time, and then execute the control in step S21 again.

[0029] When peak power consumption peak cut control is started and the margin α becomes sufficiently large, the air conditioning control unit 52 and the curtain control unit 53 may terminate the peak cut control. When peak cut control is terminated, the air conditioning control unit 52 performs the air conditioning control described using Figures 4 and 5. The curtain control unit 53 performs the control described using Figure 6. In the flowchart of Figure 8, when curtain 41 is fully closed, curtain 40 is closed, and when both curtain 41 and curtain 40 are fully closed, the target temperature is raised. However, even if curtain 41 is not fully closed, if it is closed to a predetermined degree or more and the margin α is less than or equal to a predetermined value β, curtain 40 may be closed. Similarly, even if both curtain 41 and curtain 40 are not fully closed, if at least one of curtain 41 and curtain 40 is closed to a predetermined degree or more and the margin α is less than or equal to a predetermined value β, the target temperature of the cultivation shelf 10 may be raised.

[0030] 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 to 8.

[0031] In the flowchart of Figure 8, the order of curtain control (steps S11 to S18) and target temperature control (steps S19 to S21) may be reversed. That is, when the margin α is less than or equal to a predetermined value β (step S20), the air conditioning control unit 52 first raises the target temperature (step S21). If the margin α is still less than or equal to a predetermined value β (step S12), the control is performed to close the first curtain (step S13). Furthermore, if the margin α is still less than or equal to a predetermined value β even after the first curtain is completely closed (step S16), the control is performed to close the second curtain (step S17). In this way, by correcting the temperature target first and then performing curtain control, more solar radiation enters compared to when curtain control is performed first, which is effective when prioritizing solar radiation intake over maintaining the temperature environment.

[0032] (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. The opening and closing of curtains 40 and 41 are controlled based on the temperature difference T between the cultivation shelf temperature and the target temperature. Through these controls, the yield of plants P can be improved by taking in maximum sunlight while maintaining the leaf temperature of the cultivation shelf 10 at the target temperature. With respect to the two air conditioners 30 and 31, when the heat load is low, only one air conditioner 30 is used for cooling, and when the heat load is high, the second air conditioner 31 is also used for cooling, thereby reducing electricity costs. By performing curtain control in parallel with the air conditioning control by air conditioners 30 and 31, the load on air conditioners 30 and 31 can be suppressed, and power consumption can be reduced.

[0033] Furthermore, while controlling the temperature of the cultivation shelves to the target temperature through these controls, when the power consumption of the air conditioners 30 and 31 approaches a threshold Th, peak power consumption reduction control is initiated. Specifically, the curtain control unit 53 first closes the curtain 41 to block out external light, thereby reducing the load on the air conditioners 30 and 31. If the power consumption still does not decrease sufficiently, the curtain control unit 53 further reduces the load on the air conditioners 30 and 31 by closing the curtain 40 to block out external light. If the power consumption still does not decrease sufficiently, the air conditioning control unit 52 reduces the load on the air conditioners 30 and 31 by briefly raising the target temperature of the cultivation shelves 10 within a range that does not affect the growth of the plants P. This reduces the power consumption of the air conditioners 30 and 31. With peak power consumption reduction control, for example, even during summer heat load operation, it is possible to operate with the maximum power peak suppressed as much as possible, and the cultivation greenhouse 100 can be operated within a predetermined cost. By maintaining a low-temperature environment inside the cultivation greenhouse 100 while suppressing power consumption, the yield of plant P can be increased.

[0034] 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.

[0035] In the above embodiment, the case of cooling the inside of the cultivation greenhouse was explained as an example, but the same control can be applied when heating the inside of the cultivation greenhouse. For example, when the air conditioning control unit 52 receives the cultivation shelf temperature minus the target temperature as input, it calculates the set temperature to command the air conditioners 30 and 31 based on the heating intensity calculator which outputs the heating intensity. For example, the heating intensity calculator outputs the temperature difference between the temperature measured by the temperature sensor of the air conditioner and the set temperature to be commanded to the air conditioner as the heating intensity, 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, it outputs a heating intensity of, for example, 3 according to this temperature difference of 5. The air conditioning control unit 52 obtains the 3 output by the heating intensity calculator and adds 3 to the temperature measured by the temperature sensor C2 to calculate the set temperature to command 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 above a threshold, the air conditioners 30 and 31 may be operated in fan mode. The curtain control unit 53 receives the cultivation shelf temperature minus the target temperature and controls the opening and closing of the curtains (curtains 40 and 41) based on an opening and closing control value calculator that outputs the opening and closing direction and speed of the curtains (open the curtains when the heat load is high). When peak power consumption reduction operation is performed, the target temperature of the air conditioners 30 and 31 is lowered for a short time. For the curtains, opening and closing is controlled by balancing the reduction in solar radiation due to closing the curtains with the heat retention effect due to insulation.

[0036] Figure 9 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 also allocates a storage area in the auxiliary storage 903 to store the data being processed according to the program.

[0037] 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.

[0038] 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.

[0039] <Note> The control device, cultivation house, and control method described in each embodiment can be understood, for example, as follows.

[0040] (1) The control device according to the first embodiment includes an acquisition unit that acquires the power consumption of an air conditioner that provides air conditioning in a cultivation greenhouse, an air conditioning control unit that performs air conditioning control by the air conditioner so that the temperature around the cultivation shelves in the cultivation greenhouse reaches a predetermined target temperature, and a determination unit that determines to perform power consumption peak cut control to reduce power consumption when the difference between the power consumption of the air conditioner and a predetermined threshold is less than or equal to a predetermined value, and when the determination unit decides to perform the power consumption peak cut control, the air conditioning control unit changes the target temperature in a direction that reduces the load on the air conditioner when controlling the temperature around the cultivation shelves with the air conditioner to reach the target temperature, and performs air conditioning control by the air conditioner. This makes it possible to reduce the power consumption required for temperature control.

[0041] (2) The control device according to the second embodiment is the control device of (1), further comprising a curtain control unit that controls the opening and closing of a curtain provided on the ceiling of the cultivation greenhouse, wherein when the decision unit decides to perform peak power consumption cut control, the curtain control unit closes the curtain before the air conditioning control unit changes the target temperature and starts air conditioning control. This reduces the load on the air conditioner and reduces power consumption.

[0042] (3) The control device according to the third aspect is the control device of (2), wherein the air-conditioning control unit changes the target temperature and starts air-conditioning control if the difference between the power consumption and the threshold value is less than or equal to a predetermined value after the curtain is closed to a predetermined opening degree. As a result, the opportunity to perform air-conditioning control in a state where the target temperature is increased can be reduced, and the influence on plant growth can be suppressed.

[0043] (4) The control device according to the fourth aspect is the control device of (2), wherein the air-conditioning control unit performs control to close the curtain to a predetermined opening degree if the difference between the power consumption and the threshold value is less than or equal to a predetermined value after changing the target temperature and starting air-conditioning control. As a result, the power consumption can be suppressed while taking in more solar radiation.

[0044] (5) The control device according to the fifth aspect is the control device of (2) to (4), wherein two curtains are provided on the ceiling of the cultivation house, and the two curtains include either or both of a curtain that blocks infrared rays and a curtain that blocks visible light. When the determination unit determines to perform power consumption peak cut control, the curtain control unit closes the first one of the two curtains to a predetermined opening degree. As a result, while suppressing the heat load in the house, solar radiation (visible light) can be taken into the cultivation house as much as possible.

[0045] (6) The control device according to the sixth aspect is the control device of (5), wherein the curtain control unit closes the second curtain to a predetermined opening degree if the difference between the power consumption and the threshold value is less than or equal to a predetermined value after closing the first curtain to a predetermined opening degree. As a result, the opportunity for solar radiation (visible light) into the cultivation house to be restricted can be reduced. By closing the light-shielding curtain, the load on the air conditioner can be reduced.

[0046] (7) The control device according to the seventh aspect is the control device according to (5). When one of the two curtains blocks infrared rays and the other curtain blocks visible light, the curtain control unit controls to close the curtain that blocks infrared rays as the first curtain. After closing the curtain that blocks infrared rays to a predetermined opening degree, if the difference between the power consumption and the threshold value is less than or equal to a predetermined value, control is performed to close the curtain that blocks visible light as the second curtain. Thus, by first closing the curtain that blocks infrared rays and then closing the light-blocking curtain, it is possible to reduce the load on the air conditioner while taking in sunlight into the cultivation house as much as possible.

[0047] (8) The cultivation house according to the eighth aspect includes a building that houses cultivation shelves, an air conditioner that air-conditions the building, a power monitor that measures the power consumption of the air conditioner, and the control device according to (1) to (7).

[0048] (9) The cultivation house according to the ninth aspect includes a building that houses cultivation shelves, an air conditioner that air-conditions the building, a power monitor that measures the power consumption of the air conditioner, a curtain provided on the ceiling portion of the building, and the control device according to (2) to (7).

[0049] (10) The control method according to the tenth aspect includes a step of obtaining the power consumption of an air conditioner that air-conditions the inside of a cultivation house, a step of performing air-conditioning control by the air conditioner so that the temperature around the cultivation shelves in the cultivation house becomes a predetermined target temperature, and a step of determining to perform power consumption peak cut control for reducing power consumption when the difference between the power consumption of the air conditioner and a predetermined threshold value becomes less than or equal to a predetermined value. In the step of determining, when it is determined to perform the power consumption peak cut control, in the step of performing the air-conditioning control, when controlling the air conditioner so that the temperature around the cultivation shelves becomes the target temperature, the target temperature is changed in a direction in which the load on the air conditioner becomes smaller, and the air-conditioning control is performed by the air conditioner.

[0050] According to the above-described control device, cultivation house, and control method, it is possible to reduce the power consumption required for temperature control while controlling the temperature inside the house to a temperature suitable for plant growth.

[0051] 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 44...Interior lining 45...Exterior lining 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 power consumption of an air conditioner that provides air conditioning in a cultivation greenhouse; an air conditioning control unit that controls the air conditioner so that the temperature around the cultivation shelves in the cultivation greenhouse reaches a predetermined target temperature; and a determination unit that determines to perform power consumption peak cut control to reduce power consumption when the difference between the power consumption of the air conditioner and a predetermined threshold is less than or equal to a predetermined value, wherein when the determination unit determines to perform the power consumption peak cut control, the air conditioning control unit changes the target temperature in a direction that reduces the load on the air conditioner and performs air conditioning control by the air conditioner when the air conditioner controls the temperature around the cultivation shelves to reach the target temperature.

2. The control device according to claim 1, further comprising: a curtain control unit for controlling the opening and closing of a curtain provided on the ceiling of the cultivation greenhouse, wherein when the determination unit decides to perform peak power consumption cut control, the curtain control unit closes the curtain before the air conditioning control unit changes the target temperature and starts air conditioning control.

3. The control device according to claim 2, wherein, after the curtain has been closed to a predetermined opening, if the difference between the power consumption and a threshold is less than or equal to a predetermined value, the air conditioning control unit changes the target temperature and starts air conditioning control.

4. The control device according to claim 2, wherein, after changing the target temperature and starting air conditioning control, if the difference between the power consumption and a threshold is less than or equal to a predetermined value, the control device performs control to close the curtain to a predetermined opening degree.

5. The control device according to any one of claims 2 to 4, wherein two curtains are provided on the ceiling of the cultivation greenhouse, and the two curtains include either or both of a curtain that blocks infrared rays and a curtain that blocks visible light, and the curtain control unit closes one of the two curtains to a predetermined opening when the determination unit decides to perform peak power consumption cut control.

6. The control device according to claim 5, wherein the curtain control unit closes the first curtain to a predetermined opening, and if the difference between the power consumption and the threshold is less than or equal to a predetermined value, it closes the second curtain to a predetermined opening.

7. In the case where one of the two curtains is an infrared-blocking curtain and the other is a visible-light-blocking curtain, the curtain control unit controls the first curtain to close the infrared-blocking curtain, and after closing the infrared-blocking curtain to a predetermined opening, if the difference between the power consumption and the threshold is less than or equal to a predetermined value, controls the second curtain to close the visible-light-blocking curtain. The control device according to claim 5.

8. A cultivation greenhouse comprising: a building for housing cultivation shelves; an air conditioner for providing air conditioning for the building; a power monitor for measuring the power consumption of the air conditioner; and the control device described in claim 1.

9. A cultivation greenhouse comprising: a building for housing cultivation shelves; an air conditioner for providing air conditioning for the building; a power monitor for measuring the power consumption of the air conditioner; a curtain provided on the ceiling of the building; and a control device according to any one of claims 2 to 4.

10. A control method comprising: a step of obtaining the power consumption of an air conditioner that provides air conditioning in a cultivation greenhouse; a step of performing air conditioning control by the air conditioner so that the temperature around the cultivation shelves in the cultivation greenhouse reaches a predetermined target temperature; and a step of deciding to perform power consumption peak cut control to reduce power consumption when the difference between the power consumption of the air conditioner and a predetermined threshold falls below a predetermined value, wherein in the step of deciding to perform power consumption peak cut control, if it is decided in the step of deciding to perform power consumption peak cut control, in the step of performing air conditioning control, when the air conditioner controls the temperature around the cultivation shelves to reach the target temperature, the target temperature is changed in a direction that reduces the load on the air conditioner and air conditioning control is performed by the air conditioner.

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