Temperature control method, temperature control device, temperature control program, and temperature control system

Abstract

To provide a technique that can reliably prevent occurrence of dew condensation on a surface of fruit.SOLUTION: A temperature control method in a temperature controller 1 acquires an internal temperature and internal humidity of a culture facility 100, and sequentially switches between a first operation mode, a second operation mode and a third operation mode, thus controlling the internal temperature in the culture facility 100. In the first operation mode, an air conditioning appliance 14 is operated so that the internal temperature is at a prescribed target temperature with a side window 121 and a skylight 171 closed, where the side window 121 and the skylight 171 can be opened and closed and partition inside and outside of the culture facility 100. In the second operation mode, an internal dew point temperature of the culture facility 100 is calculated on the basis of the internal temperature and internal humidity, and the air conditioning appliance 14 is operated so that a surface temperature of fruit is higher than an internal dew point temperature with the side window 121 and the skylight 171 closed. In the third operation mode, the operation of the air conditioning appliance 14 is stopped with the side window 121 and the skylight 171 opened.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a technology for controlling the internal temperature of a fruit cultivation facility. [Background technology]

[0002] In the agricultural field, greenhouse cultivation using steel frame greenhouses or pipe greenhouses (hereafter abbreviated as "greenhouses") has become widespread in recent years.

[0003] In greenhouse cultivation, the greenhouse in which the vegetables are grown is isolated from the outside world, allowing for environmental conditions inside the greenhouse that are different from those of the outside world. This reduces the impact of climate or weather conditions, making it possible to grow vegetables over long periods of time or throughout the year, and realizing a stable supply of vegetables. Furthermore, it makes it possible to grow and produce vegetables even in areas where it was previously difficult to do so, and it is attracting attention from the perspective of the SDGs (Sustainable Development Goals) as it also leads to local production for local consumption and the reduction of food miles.

[0004] It is generally known that the greater the difference in temperature between day and night, the tastier the fruit becomes.

[0005] However, in subtropical regions, for example, there is almost no difference in temperature between day and night, so it is thought that the temperature difference between day and night occurs when an air conditioner cools the inside of a greenhouse at night.

[0006] Here, in order for the air conditioner to cool the inside of the house at night, it is necessary to close the windows that can be opened and closed in the house. However, if the windows are closed during the day, the temperature inside the house becomes too high, so it is necessary to open the windows during the day.

[0007] If the windows are closed at night and the inside of the greenhouse is cooled by an air conditioner, and then the windows are opened the next morning, the temperature of the fruit surface will differ greatly from the temperature inside the greenhouse. When the cooled fruit comes into contact with the hot, humid air from outside, condensation may form on the fruit surface. Condensation on the fruit surface is thought to be one of the causes of fruit cracking, and is also known to be a cause of the spread of fungi (mold, etc.).

[0008] For example, Patent Document 1 discloses a fruit cracking prevention device that adjusts the temperature inside a cherry heating facility to adjust the daytime temperature and humidity inside the facility to a range within which moisture can evaporate from the tree body including the cherry fruit, and below a value that does not cause condensation on the cherry fruit. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] JP 2002-153147 A Summary of the Invention [Problem to be solved by the invention]

[0010] However, in the above conventional technology, the temperature in the facility is adjusted based on the humidity in the facility to adjust the temperature and humidity in the facility during the daytime to values ​​that do not cause condensation on the cherry fruit, but the surface temperature of the fruit is not taken into consideration. Therefore, with the above conventional technology, it is difficult to reliably prevent condensation from forming on the surface of the fruit, and further improvements are considered necessary.

[0011] The present disclosure has been made to solve the above problems, and aims to provide a technology that can reliably prevent condensation from occurring on the surface of fruit. [Means for solving the problem]

[0012] A temperature control method according to one embodiment of the present disclosure is a temperature control method in a temperature control device that controls the internal temperature of a fruit cultivation facility, and controls the internal temperature of the cultivation facility by acquiring the internal temperature and internal humidity of the cultivation facility and sequentially switching between a first operating mode, a second operating mode, and a third operating mode, wherein the first operating mode operates an air conditioning device so that the internal temperature becomes a predetermined target temperature with an openable window separating the inside and outside of the cultivation facility closed, the second operating mode calculates an internal dew point temperature of the cultivation facility based on the internal temperature and the internal humidity, and operates the air conditioning device so that the surface temperature of the fruit becomes higher than the internal dew point temperature with the window closed, and the third operating mode stops the air conditioning device with the window open. Effect of the Invention

[0013] According to the present disclosure, it is possible to reliably prevent condensation from occurring on the surface of fruit. [Brief description of the drawings]

[0014] [Figure 1] 1 is an overall diagram showing the configuration of a cultivation system in embodiment 1 of the present disclosure. [Diagram 2] FIG. 1 is a block diagram showing a configuration of a temperature control device according to a first embodiment of the present disclosure. [Diagram 3] 4 is a flowchart for illustrating a temperature control process of the temperature control device 1 in the first embodiment of the present disclosure. [Figure 4] 4 is a flowchart for explaining the dew condensation prevention process in step S11 of FIG. 3. [Diagram 5] 4 is a flowchart for explaining a window opening process in step S12 of FIG. 3. [Figure 6] 13 is a flowchart illustrating a window opening process according to a first modified example of the first embodiment of the present disclosure. [Figure 7] 13 is a flowchart illustrating a dew condensation prevention process in a second modified example of the first embodiment of the present disclosure. [Figure 8] FIG. 11 is an overall diagram showing the configuration of a cultivation system in a second embodiment of the present disclosure. [Figure 9] FIG. 11 is a block diagram showing a configuration of a temperature control device according to a second embodiment of the present disclosure. [Figure 10] 11 is a flowchart for explaining a dew condensation prevention process according to a second embodiment of the present disclosure. [Figure 11] FIG. 11 is an overall diagram showing the configuration of a cultivation system in embodiment 3 of the present disclosure. [Figure 12] FIG. 11 is a block diagram showing a configuration of a temperature control device according to a third embodiment of the present disclosure. [Figure 13] FIG. 13 is a diagram showing an example of a surface temperature estimation table stored in a memory in the third embodiment of the present disclosure. [Figure 14] 13 is a flowchart for explaining a dew condensation prevention process according to a third embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] (Findings on which this disclosure is based) In greenhouse cultivation, high temperatures above 30°C result in poor fruit set, enlargement, and coloring. Also, temperatures above 35°C reduce pollen fertility and cause fruit drop. Also, high nighttime temperatures increase loss due to respiration, and fruit enlargement is poor. On the other hand, daytime temperatures below 20°C and nighttime temperatures between 4°C and 8°C promote differentiation and development of each organ in the flower, increase the number of locules, and increase the occurrence of irregularly shaped fruits.

[0016] There is also an appropriate range for relative humidity; for example, if the relative humidity exceeds 90%, diseases such as leaf mold become more likely to occur. Furthermore, in an environment with extremely high relative humidity, condensation may form on the surface of the fruit. It is said that condensation on the surface of the fruit leads to cracking. Fruit that has cracked has a reduced commercial value and is often unsellable. In addition, condensation on the surface of the fruit can also cause the spread of diseases such as leaf mold.

[0017] On the other hand, when the relative humidity is extremely low, plants close their stomata to prevent excessive transpiration, suppressing photosynthesis.

[0018] Although the temperature and humidity inside the greenhouse are sometimes controlled manually by the vegetable grower, in recent years, they are often controlled automatically using an integrated environmental control device based on measurement data such as temperature, humidity, and light intensity inside and outside the greenhouse. In addition, air conditioning equipment such as heat pump air conditioners and combustion-type heaters are expensive to operate. For this reason, the use of air conditioning equipment is often limited to a certain extent, and control is often performed in combination with ventilation and shading.

[0019] In addition, in greenhouse cultivation, environmental control equipment such as side windows, skylights, ventilation fans, curtains, air conditioning equipment (heat pump air conditioners and combustion-type heaters, etc.), and mist are controlled so that the environment inside the greenhouse is appropriate for the growth of the plants (vegetables) being cultivated, that is, so that the environment inside the greenhouse is suitable for the growth of the vegetables being cultivated.

[0020] For example, in the case of cultivating tomatoes, the optimum temperature for growth is said to be in the range of 5 to 40°C, more preferably 10 to 35°C, with the optimum temperature during the day being 25 to 30°C and the optimum temperature at night being 10 to 15°C. Environmental control is carried out so that the temperature inside the greenhouse falls within the above ranges.

[0021] In addition, the appropriate environment inside the greenhouse differs between daytime, when photosynthesis occurs, and nighttime, when only respiration occurs. In the case of tomatoes, the temperature inside the greenhouse is controlled to a target value of 25-30°C during the day and 10-15°C at night.

[0022] Therefore, when the temperature control is switched from nighttime to daytime during the day, the temperature inside the greenhouse changes significantly. At this time, depending on the temperature and humidity conditions inside the greenhouse, the difference between the surface temperature of the fruit and the temperature inside the greenhouse may become large, which may result in condensation on the surface of the fruit.

[0023] Specific examples are shown below.

[0024] The cultivation area is assumed to be a hot and humid climate region, such as a subtropical region. In hot and humid climate regions, the temperature is high throughout the day and night, and the humidity is also high. In these regions, the greenhouse is closed at night and cooled using a heat pump air conditioner or similar. However, after sunrise, the temperature inside the greenhouse rises due to the sunlight, and the heat pump air conditioner cannot cool it sufficiently. Therefore, during the day, the heat pump air conditioner is stopped and outside air is actively introduced by ventilating. This prevents the temperature from rising too much.

[0025] Consider the case of tomato cultivation. Temperature control by cooling the greenhouse with a heat pump air conditioner at night switches to temperature control by introducing outside air around sunrise, and this timing can cause condensation on the tomato fruits.

[0026] This is for the following reasons.

[0027] (1) During the night-time cooling period, the temperature inside the greenhouse is lower than the outside air, and the temperature of the tomato fruit is similarly lower.

[0028] (2) When switching to temperature control by introducing outside air, air that is hotter and more humid than inside the greenhouse flows in.

[0029] (3) Tomato fruits have a large heat capacity. Therefore, even if the surrounding air temperature rises suddenly, the temperature of the tomato fruit rises slowly.

[0030] (4) As a result, immediately after switching to temperature control using outside air, the high-temperature, high-humidity air that flows into the greenhouse is cooled by the tomato fruits. As the air around the tomato fruits drops below its dew point temperature, condensation forms on the surfaces of the tomato fruits.

[0031] In order to solve the above problems, a temperature control method according to one embodiment of the present disclosure is a temperature control method in a temperature control device that controls the internal temperature of a fruit cultivation facility, which acquires the internal temperature and internal humidity of the cultivation facility and controls the internal temperature of the cultivation facility by sequentially switching between a first operating mode, a second operating mode, and a third operating mode, wherein the first operating mode operates an air conditioning device so that the internal temperature becomes a predetermined target temperature with an openable window separating the inside and outside of the cultivation facility closed, the second operating mode calculates an internal dew point temperature of the cultivation facility based on the internal temperature and the internal humidity, and operates the air conditioning device so that the surface temperature of the fruit becomes higher than the internal dew point temperature with the window closed, and the third operating mode stops the air conditioning device with the window open.

[0032] According to this configuration, at night, with the windows closed, the air conditioner operates so that the internal temperature of the cultivation facility becomes a predetermined target temperature. From before sunrise to after sunrise, with the windows closed, the air conditioner operates so that the surface temperature of the fruit becomes higher than the internal dew point temperature of the cultivation facility. Then, when the internal temperature of the cultivation facility approaches the external temperature of the cultivation facility, the air conditioner stops with the windows open. Therefore, when the windows are opened after sunrise, the internal temperature of the cultivation facility approaches the external temperature of the cultivation facility and the surface temperature of the fruit becomes higher than the internal dew point temperature of the cultivation facility, so that condensation on the surface of the fruit can be reliably prevented.

[0033] In the above temperature control method, the operation mode may be shifted from the second operation mode to the third operation mode after a predetermined time has elapsed since sunrise.

[0034] According to this configuration, until a predetermined time has elapsed from sunrise, the windows are closed and the air conditioner operates so that the surface temperature of the fruit is higher than the internal dew point temperature of the cultivation facility, and after the predetermined time has elapsed from sunrise, the windows are opened and the air conditioner stops. Therefore, by setting the predetermined time to a time when the internal temperature of the cultivation facility approaches the external temperature of the cultivation facility, it is possible to reliably prevent condensation from forming on the surface of the fruit.

[0035] In the above temperature control method, when the internal temperature reaches a temperature that is a limit for growth of the fruit, the operation mode may be shifted from the second operation mode to the third operation mode.

[0036] With this configuration, the air conditioner operates with the windows closed so that the surface temperature of the fruit is higher than the internal dew point temperature of the cultivation facility until the internal temperature reaches the limit temperature for fruit growth, and when the internal temperature reaches the limit temperature for fruit growth, the air conditioner stops with the windows open. Therefore, when the internal temperature of the cultivation facility reaches the limit temperature for fruit growth, even if the internal temperature of the cultivation facility is approaching or exceeding the external temperature of the cultivation facility and the window is opened, condensation can be prevented from occurring on the surface of the fruit.

[0037] In addition, in the above temperature control method, the external temperature and external humidity of the cultivation facility may be acquired, an external dew point temperature of the cultivation facility may be calculated based on the external temperature and the external humidity, and when the surface temperature of the fruit becomes higher than the external dew point temperature, the second operation mode may be transitioned to the third operation mode.

[0038] According to this configuration, when the surface temperature of the fruit is equal to or lower than the external dew point temperature of the cultivation facility, the window is closed and the air conditioner operates so that the surface temperature of the fruit is higher than the internal dew point temperature of the cultivation facility, and when the surface temperature of the fruit is higher than the external dew point temperature of the cultivation facility, the window is opened and the air conditioner stops. Therefore, when the window is opened, the surface temperature of the fruit is higher than the external dew point temperature of the cultivation facility, so that condensation on the surface of the fruit can be prevented.

[0039] In the above temperature control method, in the second operation mode, the surface temperature of the fruit may further be obtained from a sensor that measures the surface temperature of the fruit.

[0040] According to this configuration, an accurate fruit surface temperature can be obtained from the sensor that measures the fruit surface temperature, so that condensation on the surface of the fruit can be more reliably prevented.

[0041] In the above temperature control method, in the second operation mode, a surface temperature of the fruit may be further estimated.

[0042] According to this configuration, since the surface temperature of the fruit is estimated, a sensor for measuring the surface temperature of the fruit is not required, and the configuration can be simplified.

[0043] In addition, in the above temperature control method, the estimated value corresponding to the internal temperature at the time of transition to the second operation mode and the elapsed time since the time of transition to the second operation mode may be extracted from a table that corresponds the internal temperature of the cultivation facility at the time of transition to the second operation mode and the elapsed time since the time of transition to the second operation mode to an estimated value of the surface temperature of the fruit.

[0044] According to this configuration, the surface temperature of the fruit can be easily estimated based on the internal temperature at the time of transition to the second operation mode and the elapsed time from the time of transition to the second operation mode.

[0045] In the above temperature control method, in the third operation mode, the window may be opened stepwise at predetermined time intervals.

[0046] According to this configuration, the windows are opened in stages at predetermined time intervals, so that the temperature inside the cultivation facility can be gradually brought closer to the temperature outside the cultivation facility.

[0047] A temperature control device according to another aspect of the present disclosure is a temperature control device that controls the internal temperature of a fruit cultivation facility, and includes an acquisition unit that acquires the internal temperature and internal humidity of the cultivation facility, and a control unit that controls the internal temperature of the cultivation facility by sequentially switching between a first operating mode, a second operating mode, and a third operating mode, wherein the first operating mode operates an air conditioning device so that the internal temperature becomes a predetermined target temperature with an openable window separating the inside and outside of the cultivation facility closed, the second operating mode calculates an internal dew point temperature of the cultivation facility based on the internal temperature and the internal humidity, and operates the air conditioning device so that the surface temperature of the fruit is higher than the internal dew point temperature with the window closed, and the third operating mode stops the air conditioning device with the window open.

[0048] According to this configuration, at night, with the windows closed, the air conditioner operates so that the internal temperature of the cultivation facility becomes a predetermined target temperature. From before sunrise to after sunrise, with the windows closed, the air conditioner operates so that the surface temperature of the fruit becomes higher than the internal dew point temperature of the cultivation facility. Then, when the internal temperature of the cultivation facility approaches the external temperature of the cultivation facility, the air conditioner stops with the windows open. Therefore, when the windows are opened after sunrise, the internal temperature of the cultivation facility approaches the external temperature of the cultivation facility and the surface temperature of the fruit becomes higher than the internal dew point temperature of the cultivation facility, so that condensation on the surface of the fruit can be reliably prevented.

[0049] A temperature control program according to another aspect of the present disclosure is a temperature control program for controlling the internal temperature of a fruit cultivation facility, which causes a computer to function to control the internal temperature of the cultivation facility by acquiring the internal temperature and internal humidity of the cultivation facility and sequentially switching between a first operating mode, a second operating mode, and a third operating mode, wherein the first operating mode operates an air conditioning device so that the internal temperature becomes a predetermined target temperature with an openable window separating the inside and outside of the cultivation facility closed, the second operating mode calculates an internal dew point temperature of the cultivation facility based on the internal temperature and the internal humidity, and operates the air conditioning device so that the surface temperature of the fruit becomes higher than the internal dew point temperature with the window closed, and the third operating mode stops the air conditioning device with the window open.

[0050] According to this configuration, at night, with the windows closed, the air conditioner operates so that the internal temperature of the cultivation facility becomes a predetermined target temperature. From before sunrise to after sunrise, with the windows closed, the air conditioner operates so that the surface temperature of the fruit becomes higher than the internal dew point temperature of the cultivation facility. Then, when the internal temperature of the cultivation facility approaches the external temperature of the cultivation facility, the air conditioner stops with the windows open. Therefore, when the windows are opened after sunrise, the internal temperature of the cultivation facility approaches the external temperature of the cultivation facility and the surface temperature of the fruit becomes higher than the internal dew point temperature of the cultivation facility, so that condensation on the surface of the fruit can be reliably prevented.

[0051] A temperature control system according to another aspect of the present disclosure comprises a temperature control device that controls the internal temperature of a fruit cultivation facility, an air conditioning device, and an openable / closable window that separates the inside and outside of the cultivation facility, wherein the temperature control device comprises an acquisition unit that acquires the internal temperature and internal humidity of the cultivation facility, and a control unit that controls the internal temperature of the cultivation facility by sequentially switching between a first operating mode, a second operating mode, and a third operating mode, wherein the first operating mode operates the air conditioning device so that the internal temperature becomes a predetermined target temperature with the window closed, the second operating mode calculates an internal dew point temperature of the cultivation facility based on the internal temperature and the internal humidity, and operates the air conditioning device so that the surface temperature of the fruit is higher than the internal dew point temperature with the window closed, and the third operating mode stops the air conditioning device with the window open.

[0052] According to this configuration, at night, with the windows closed, the air conditioner operates so that the internal temperature of the cultivation facility becomes a predetermined target temperature. From before sunrise to after sunrise, with the windows closed, the air conditioner operates so that the surface temperature of the fruit becomes higher than the internal dew point temperature of the cultivation facility. Then, when the internal temperature of the cultivation facility approaches the external temperature of the cultivation facility, the air conditioner stops with the windows open. Therefore, when the windows are opened after sunrise, the internal temperature of the cultivation facility approaches the external temperature of the cultivation facility and the surface temperature of the fruit becomes higher than the internal dew point temperature of the cultivation facility, so that condensation on the surface of the fruit can be reliably prevented.

[0053] A temperature control method according to another aspect of the present disclosure is a temperature control method in a temperature control device that controls the internal temperature of a fruit cultivation facility, which controls the internal temperature of the cultivation facility by obtaining a surface temperature of the fruit from a sensor that measures the surface temperature of the fruit, and sequentially switching between a first operating mode, a second operating mode, and a third operating mode, wherein the first operating mode operates an air conditioning device so that the internal temperature becomes a predetermined target temperature with an openable window separating the inside and outside of the cultivation facility closed, the second operating mode calculates an internal dew point temperature of the cultivation facility based on the internal temperature and the internal humidity, and operates the air conditioning device so that the surface temperature of the fruit becomes higher than the internal dew point temperature with the window closed, and the third operating mode stops the air conditioning device with the window open.

[0054] According to this configuration, at night, with the windows closed, the air conditioner operates so that the internal temperature of the cultivation facility becomes a predetermined target temperature. From before sunrise to after sunrise, with the windows closed, the air conditioner operates so that the surface temperature of the fruit becomes higher than the internal dew point temperature of the cultivation facility. Then, when the internal temperature of the cultivation facility approaches the external temperature of the cultivation facility, the air conditioner stops with the windows open. Therefore, when the windows are opened after sunrise, the internal temperature of the cultivation facility approaches the external temperature of the cultivation facility and the surface temperature of the fruit becomes higher than the internal dew point temperature of the cultivation facility, so that condensation on the surface of the fruit can be reliably prevented.

[0055] A temperature control device according to another aspect of the present disclosure is a temperature control device that controls the internal temperature of a fruit cultivation facility, and includes an acquisition unit that acquires the surface temperature of the fruit from a sensor that measures the surface temperature of the fruit, and a control unit that controls the internal temperature of the cultivation facility by sequentially switching between a first operating mode, a second operating mode, and a third operating mode, wherein the first operating mode operates an air conditioning device so that the internal temperature becomes a predetermined target temperature with an openable window separating the inside and outside of the cultivation facility closed, the second operating mode calculates an internal dew point temperature of the cultivation facility based on the internal temperature and the internal humidity, and operates the air conditioning device so that the surface temperature of the fruit becomes higher than the internal dew point temperature with the window closed, and the third operating mode stops the air conditioning device with the window open.

[0056] According to this configuration, at night, with the windows closed, the air conditioner operates so that the internal temperature of the cultivation facility becomes a predetermined target temperature. From before sunrise to after sunrise, with the windows closed, the air conditioner operates so that the surface temperature of the fruit becomes higher than the internal dew point temperature of the cultivation facility. Then, when the internal temperature of the cultivation facility approaches the external temperature of the cultivation facility, the air conditioner stops with the windows open. Therefore, when the windows are opened after sunrise, the internal temperature of the cultivation facility approaches the external temperature of the cultivation facility and the surface temperature of the fruit becomes higher than the internal dew point temperature of the cultivation facility, so that condensation on the surface of the fruit can be reliably prevented.

[0057] A temperature control program according to another aspect of the present disclosure is a temperature control program for controlling the internal temperature of a fruit cultivation facility, which causes a computer to function to control the internal temperature of the cultivation facility by obtaining the surface temperature of the fruit from a sensor that measures the surface temperature of the fruit and sequentially switching between a first operating mode, a second operating mode, and a third operating mode, wherein the first operating mode operates an air conditioning device so that the internal temperature becomes a predetermined target temperature with an openable window separating the inside and outside of the cultivation facility closed, the second operating mode calculates an internal dew point temperature of the cultivation facility based on the internal temperature and the internal humidity, and operates the air conditioning device so that the surface temperature of the fruit becomes higher than the internal dew point temperature with the window closed, and the third operating mode stops the air conditioning device with the window open.

[0058] According to this configuration, at night, with the windows closed, the air conditioner operates so that the internal temperature of the cultivation facility becomes a predetermined target temperature. From before sunrise to after sunrise, with the windows closed, the air conditioner operates so that the surface temperature of the fruit becomes higher than the internal dew point temperature of the cultivation facility. Then, when the internal temperature of the cultivation facility approaches the external temperature of the cultivation facility, the air conditioner stops with the windows open. Therefore, when the windows are opened after sunrise, the internal temperature of the cultivation facility approaches the external temperature of the cultivation facility and the surface temperature of the fruit becomes higher than the internal dew point temperature of the cultivation facility, so that condensation on the surface of the fruit can be reliably prevented.

[0059] A temperature control system according to another aspect of the present disclosure comprises a temperature control device that controls the internal temperature of a fruit cultivation facility, an air conditioning device, an openable and closable window that separates the inside and outside of the cultivation facility, and a sensor that measures the surface temperature of the fruit, wherein the temperature control device comprises an acquisition unit that acquires the surface temperature of the fruit from the sensor, and a control unit that controls the internal temperature of the cultivation facility by sequentially switching between a first operating mode, a second operating mode, and a third operating mode, wherein the first operating mode operates the air conditioning device so that the internal temperature becomes a predetermined target temperature with the window closed, the second operating mode calculates an internal dew point temperature of the cultivation facility based on the internal temperature and the internal humidity, and operates the air conditioning device so that the surface temperature of the fruit is higher than the internal dew point temperature with the window closed, and the third operating mode stops the air conditioning device with the window open.

[0060] According to this configuration, at night, with the windows closed, the air conditioner operates so that the internal temperature of the cultivation facility becomes a predetermined target temperature. From before sunrise to after sunrise, with the windows closed, the air conditioner operates so that the surface temperature of the fruit becomes higher than the internal dew point temperature of the cultivation facility. Then, when the internal temperature of the cultivation facility approaches the external temperature of the cultivation facility, the air conditioner stops with the windows open. Therefore, when the windows are opened after sunrise, the internal temperature of the cultivation facility approaches the external temperature of the cultivation facility and the surface temperature of the fruit becomes higher than the internal dew point temperature of the cultivation facility, so that condensation on the surface of the fruit can be reliably prevented.

[0061] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. Note that the following embodiments are examples of the present disclosure and do not limit the technical scope of the present disclosure.

[0062] (Embodiment 1) FIG. 1 is an overall view showing the configuration of a cultivation system according to a first embodiment of the present disclosure.

[0063] The cultivation facility 100 is a facility for cultivating the fruit 10 in isolation from the outside world. Specifically, the cultivation facility 100 is a steel frame house or a pipe house surrounded by polyolefin, polyvinyl chloride, fluorine-based film, or the like. The fruit 10 is, for example, a tomato fruit.

[0064] The cultivation system shown in FIG. 1 includes a temperature control device 1, an internal temperature and humidity measuring device 11, a side window driving device 12, a ventilation fan 13, an air conditioner 14, a surface temperature measuring device 15, a skylight driving device 17, a side window 121 and a skylight 171.

[0065] The internal temperature and humidity measuring device 11 measures the internal temperature and humidity of the cultivation facility 100. The internal temperature and humidity measuring device 11 includes a temperature sensor 141 and a humidity sensor 142. The temperature sensor 141 measures the internal temperature of the cultivation facility 100. The humidity sensor 142 measures the internal humidity of the cultivation facility 100. The internal humidity is the relative humidity inside the cultivation facility 100. The temperature sensor 141 and the humidity sensor 142 are installed at any location inside the cultivation facility 100.

[0066] The temperature control device 1 controls the internal temperature of the cultivation facility 100 for the fruit 10. Based on data input from the internal temperature and humidity measuring device 11, the temperature control device 1 determines the degree of separation between the inside and outside of the cultivation facility 100 and the degree of change in the temperature and humidity inside the cultivation facility 100.

[0067] The air conditioner 14 changes the temperature and humidity inside the cultivation facility 100, for example, by using a heat pump. The air conditioner 14 cools the inside of the cultivation facility 100 by its cooling function, and heats the inside of the cultivation facility 100 by its heating function. When the air conditioner 14 is operating, the inside of the cultivation facility 100 can be cooled or heated more efficiently by stopping the ventilation fan 13 and closing the side windows 121 and skylights 171. Particularly at night, the temperature control device 1 operates the air conditioner 14 with the ventilation fan 13 stopped and the side windows 121 and skylights 171 closed.

[0068] The air conditioner 14 may be composed of multiple air conditioner element devices. For example, the air conditioner 14 may include multiple heat pumps. Of the multiple heat pumps, some heat pumps may perform cooling operation, and the other heat pumps may perform heating operation. This allows the temperature and humidity in the cultivation facility 100 to be precisely controlled. The air conditioner 14 may also be composed of a heat pump and a combustion heater. The heating function of the air conditioner 14 may be realized by operating the combustion heater. Furthermore, the air conditioner 14 may include a dehumidifier as an air conditioner element device.

[0069] The ventilation fan 13 is installed at the upper part of a side surface (generally a surface in the short direction) of the cultivation facility 100, and forcibly exhausts air within the cultivation facility 100 to the outside.

[0070] The temperature inside the cultivation facility 100 rises due to the incidence of sunlight, and becomes higher than the air temperature outside the cultivation facility 100. In particular, high-temperature air tends to accumulate at the upper part of the cultivation facility 100, and the ventilation fan 13 can suppress the rise in temperature inside the cultivation facility 100 by discharging this high-temperature air to the outside. Note that the cultivation system does not necessarily have to be equipped with the ventilation fan 13.

[0071] The side window 121 can be opened and closed, and separates the inside and outside of the cultivation facility 100. The side window 121 is made of a covering film that covers the side surface (longitudinal surface) of the cultivation facility 100. A straight pipe for winding up the covering film is provided below the covering film, and the side window 121 on the side surface of the cultivation facility 100 opens and closes as the straight pipe rotates.

[0072] The skylight 171 can be opened and closed, and separates the inside and outside of the cultivation facility 100. The skylight 171 is provided in the upper part of the cultivation facility 100.

[0073] When the side windows 121 and the skylight 171 are closed, the temperature inside the cultivation facility 100 rises due to the incidence of sunlight and becomes higher than the air temperature outside the cultivation facility 100. When the side windows 121 and the skylight 171 are then opened, outside air is taken into the cultivation facility 100, thereby suppressing the rise in temperature inside the cultivation facility 100.

[0074] The side window driving device 12 opens and closes the side window 121 in accordance with a control signal from the temperature control device 1. The side window driving device 12 automatically opens and closes the side window 121 by rotating a straight tube provided at the bottom of the side window 121. The side window 121 may also be opened and closed manually. When the side window 121 is opened and closed manually, the side window driving device 12 is not necessary.

[0075] The skylight driving device 17 automatically opens and closes the skylight 171 in accordance with a control signal from the temperature control device 1. The skylight 171 may also be opened and closed manually. When the skylight 171 is opened and closed manually, the skylight driving device 17 is not necessary.

[0076] The temperature sensor 141 and the humidity sensor 142 transmit the data measured by each of them to the temperature control device 1. The temperature sensor 141 and the humidity sensor 142 may transmit a voltage output corresponding to the temperature and humidity values, for example, via a cable. The temperature sensor 141 and the humidity sensor 142 may also transmit the temperature and humidity as a digital signal, for example, via a network such as a LAN (local area network).

[0077] The surface temperature measuring device 15 is, for example, a radiation thermometer, and measures the surface temperature of the fruit. The surface temperature measuring device 15 measures the surface temperature of at least one of the multiple fruits in the cultivation facility 100. The surface temperature measuring device 15 transmits the measured fruit surface temperature to the temperature control device 1.

[0078] Below, a temperature control method will be described in which, assuming fruit cultivation, the inside of the cultivation facility 100 is cooled at night and outside air is introduced into the cultivation facility 100 after sunrise.

[0079] In addition, the cultivation area is assumed to be a hot and humid area, where the nighttime outdoor temperature is, for example, 26°C and the nighttime outdoor humidity is, for example, 90%, and the daytime outdoor temperature is, for example, 32°C and the daytime outdoor humidity is, for example, 60%.

[0080] At night, the ventilation fan 13 is stopped, the side windows 121 and the skylight 171 are closed, and the air conditioner 14 performs cooling operation. In this embodiment, a case is considered in which the internal temperature of the cultivation facility 100 is set to be about 5°C lower than the outside air temperature. At this time, the internal temperature of the cultivation facility 100 is, for example, 21°C.

[0081] In this situation, if at sunrise the air conditioner 14 is stopped, the exhaust fan 13 is operated, the side windows 121 and skylights 171 are fully opened, and outside air with a temperature of 26°C and a humidity of 90% is introduced into the cultivation facility 100, the temperature of the fruit is 21°C, so the air around the fruit is cooled to 21°C. The dew point temperature of outside air with a temperature of 26°C and a humidity of 90% is approximately 24.2°C, so the air temperature around the fruit falls below the dew point temperature, and condensation occurs on the fruit.

[0082] Therefore, in order to prevent condensation from forming on the fruit, the temperature of the fruit needs to be higher than the dew point temperature of the outside air when the outside air is introduced.

[0083] FIG. 2 is a block diagram showing a configuration of the temperature control device according to the first embodiment of the present disclosure.

[0084] The temperature control device 1 shown in FIG.

[0085] The memory 102 is a storage device capable of storing various types of information, such as a random access memory (RAM), a solid state drive (SSD), or a flash memory.

[0086] The processor 101 is, for example, a CPU (Central Processing Unit), and includes an internal temperature and humidity acquisition unit 111, a fruit surface temperature acquisition unit 112, and a temperature control unit 113.

[0087] The internal temperature and humidity acquisition unit 111 acquires the internal temperature and internal humidity of the cultivation facility 100 measured by the internal temperature and humidity measuring device 11. The internal temperature and humidity acquisition unit 111 periodically acquires the internal temperature and internal humidity from the internal temperature and humidity measuring device 11 at predetermined time intervals.

[0088] The fruit surface temperature acquisition unit 112 acquires the fruit surface temperature measured by the surface temperature measurement device 15. The fruit surface temperature acquisition unit 112 periodically acquires the fruit surface temperature from the surface temperature measurement device 15 at predetermined time intervals.

[0089] The temperature control unit 113 controls the internal temperature of the cultivation facility 100 by sequentially switching between a first operation mode, a second operation mode, and a third operation mode. Here, in the first operation mode, the air conditioner 14 is operated so that the internal temperature becomes a predetermined target temperature with the openable side windows 121 and the skylight 171 separating the inside and the outside of the cultivation facility 100 being closed. In the second operation mode, the internal dew point temperature of the cultivation facility 100 is calculated based on the internal temperature and the internal humidity, and the air conditioner 14 is operated so that the surface temperature of the fruit 10 becomes higher than the internal dew point temperature with the side windows 121 and the skylight 171 being closed. In the third operation mode, the air conditioner 14 is stopped with the side windows 121 and the skylight 171 being open.

[0090] The temperature control unit 113 includes a first operation mode control unit 131, a second operation mode control unit 132, and a third operation mode control unit 133.

[0091] The first operation mode control unit 131 judges whether the current time is the nighttime cooling start time. The nighttime cooling start time is, for example, the sunset time. The first operation mode control unit 131 also judges whether the current time is the condensation prevention process start time. The condensation prevention process start time is, for example, three hours before the sunrise time. If the sunrise time is 6:00 a.m., the condensation prevention process start time is 3:00 a.m. When the first operation mode control unit 131 judges that the current time is the nighttime cooling start time but not the condensation prevention process start time, it operates the air conditioner 14 with the side windows 121 and the skylight 171 closed so that the internal temperature becomes a predetermined target temperature.

[0092] The first operation mode control unit 131 outputs a control signal to the side window drive device 12 to close the side window 121, and outputs a control signal to the skylight drive device 17 to close the skylight 171. Furthermore, with the side window 121 and the skylight 171 closed, the first operation mode control unit 131 operates the air conditioner 14 so that the internal temperature becomes a predetermined target temperature. The predetermined target temperature is, for example, 21°C. The first operation mode control unit 131 outputs a control signal to the air conditioner 14 so that the internal temperature acquired by the internal temperature and humidity acquisition unit 111 becomes the predetermined target temperature.

[0093] For example, when the internal temperature is higher than a predetermined target temperature and the air conditioner 14 is in an OFF state, the first operation mode control unit 131 outputs a control signal to the air conditioner 14 to change the air conditioner 14 to an ON state. Also, when the internal temperature is higher than a predetermined target temperature and the air conditioner 14 is in an ON state, the first operation mode control unit 131 does not output a control signal to the air conditioner 14. Also, when the internal temperature is equal to or lower than a predetermined target temperature and the air conditioner 14 is in an OFF state, the first operation mode control unit 131 does not output a control signal to the air conditioner 14. Also, when the internal temperature is equal to or lower than a predetermined target temperature and the air conditioner 14 is in an ON state, the first operation mode control unit 131 outputs a control signal to the air conditioner 14 to change the air conditioner 14 to an OFF state.

[0094] When the first operation mode control unit 131 determines that the current time is the start time for the condensation prevention treatment, the second operation mode control unit 132 calculates the internal dew point temperature of the cultivation facility 100 based on the internal temperature and internal humidity, and operates the air conditioning equipment 14 with the side windows 121 and skylight 171 closed so that the surface temperature of the fruit 10 is higher than the internal dew point temperature.

[0095] The second operation mode control unit 132 judges whether the current time is the end time of the condensation prevention process. The condensation prevention process end time is a time when a sufficient amount of time has passed since the sunrise time, for example, 8:00 a.m. The memory 102 may store a predetermined condensation prevention process end time.

[0096] The dew condensation prevention treatment end time may be a time when a predetermined time has elapsed since the sunrise time. The second operation mode control unit 132 may transition from the second operation mode to the third operation mode after a predetermined time has elapsed since the sunrise time. The predetermined time is, for example, two hours. The dew condensation prevention treatment end time may be changed according to the season. The dew condensation prevention treatment end time may be determined according to the type or size of the fruit being cultivated. The time when the internal temperature of the cultivation facility 100 rises due to sunlight after sunrise and the fruit surface temperature becomes higher than the internal dew point temperature is set as the dew condensation prevention treatment end time. The temperature of the fruit rises following the internal temperature of the cultivation facility 100. Therefore, the predetermined time may be determined by estimation or experiment.

[0097] If the second operation mode control unit 132 determines that the current time is not the end time of the condensation prevention treatment, it calculates the internal dew point temperature of the cultivation facility 100 based on the internal temperature and internal humidity, and operates the air conditioning equipment 14 with the side windows 121 and skylight 171 closed so that the surface temperature of the fruit 10 is higher than the internal dew point temperature.

[0098] The second operation mode control unit 132 calculates the internal dew point temperature of the cultivation facility 100 based on the internal temperature and internal humidity acquired by the internal temperature and humidity acquisition unit 111. The second operation mode control unit 132 calculates the internal dew point temperature based on the following formula (1).

[0099] Internal dew point temperature = 237.3 * log (internal water vapor pressure / 6.11) / (7.5 * log (10) + log (6.11 / internal water vapor pressure)) (1) The internal water vapor pressure is calculated based on the following formula (2).

[0100] Internal water vapor pressure = 6.11 * 10^(7.5 * internal temperature / (273.3 + internal temperature)) * internal humidity / 100 · · · (2) The second operation mode control unit 132 operates the air conditioner 14 so that the surface temperature of the fruit 10 is higher than the internal dew point temperature with the side window 121 and the skylight 171 closed. That is, when the fruit surface temperature is higher than the internal dew point temperature and the air conditioner 14 is on, the second operation mode control unit 132 outputs a control signal to the air conditioner 14 to change the air conditioner 14 to the off state. In addition, when the fruit surface temperature is higher than the internal dew point temperature and the air conditioner 14 is off, the second operation mode control unit 132 does not output a control signal to the air conditioner 14. In addition, when the fruit surface temperature is equal to or lower than the internal dew point temperature and the air conditioner 14 is off, the second operation mode control unit 132 outputs a control signal to the air conditioner 14 to change the air conditioner 14 to the on state. Furthermore, the second operation mode control unit 132 does not output a control signal to the air conditioner 14 when the fruit surface temperature is equal to or lower than the internal dew point temperature and the air conditioner 14 is in the on state.

[0101] In this way, the second operation mode control unit 132 operates the air conditioning equipment 14 with the side windows 121 and skylight 171 closed from the start time of the condensation prevention process to the end time of the condensation prevention process so that the surface temperature of the fruit 10 is higher than the internal dew point temperature.

[0102] The third operation mode control unit 133 stops the air conditioner 14 with the side windows 121 and skylight 171 open. When the second operation mode control unit 132 determines that the current time is the end time of the condensation prevention process, the third operation mode control unit 133 outputs a control signal to the side window drive device 12 to open the side window 121, and outputs a control signal to the skylight drive device 17 to open the skylight 171. Furthermore, when the air conditioner 14 is in the on state, the third operation mode control unit 133 stops the air conditioner 14. off The third operation mode control unit 133 outputs a control signal for changing the air conditioner 14 to the off state, to the air conditioner 14. Furthermore, when the air conditioner 14 is in the off state, the third operation mode control unit 133 does not output a control signal to the air conditioner 14.

[0103] The third operation mode control unit 133 opens the side windows 121 and skylights 171 in stages at predetermined time intervals. First, the third operation mode control unit 133 opens the side windows 121 and skylights 171, for example, 30%. Then, after a predetermined time has elapsed from the time when the side windows 121 and skylights 171 are opened, the third operation mode control unit 133 may open the side windows 121 and skylights 171 100%.

[0104] Next, the temperature control process of the temperature control device 1 in the first embodiment of the present disclosure will be described.

[0105] FIG. 3 is a flowchart for illustrating a temperature control process of the temperature control device 1 according to the first embodiment of the present disclosure.

[0106] First, in step S1, the first operation mode control unit 131 judges whether the current time is the nighttime cooling start time or not. If it is judged that the current time is not the nighttime cooling start time (NO in step S1), the judgment process of step S1 is repeated until the current time becomes the nighttime cooling start time.

[0107] On the other hand, if it is determined that the current time is the nighttime cooling start time (YES in step S1), the first operation mode control unit 131 determines whether the side window 121 and the skylight 171 are closed or not. The first operation mode control unit 131 may obtain whether the side window 121 and the skylight 171 are open or closed from the side window drive device 12 and the skylight drive device 17. The first operation mode control unit 131 may also determine whether the side window 121 and the skylight 171 are closed or not based on the detection results of sensors provided in the side window 121 and the skylight 171.

[0108] If it is determined that the side window 121 and the skylight 171 are closed (YES in step S2), the process proceeds to step S4.

[0109] On the other hand, if it is determined that the side window 121 and the skylight 171 are not closed (NO in step S2), in step S3, the first operation mode control unit 131 outputs a control signal to the side window drive device 12 to close the side window 121, and outputs a control signal to the skylight drive device 17 to close the skylight 171. Upon receiving the control signal from the first operation mode control unit 131, the side window drive device 12 closes the side window 121. Furthermore, upon receiving the control signal from the first operation mode control unit 131, the skylight drive device 17 closes the skylight 171.

[0110] Next, in step S4, the first operation mode control unit 131 judges whether the current time is the dew condensation prevention process start time or not. If it is judged that the current time is not the dew condensation prevention process start time (NO in step S4), in step S5, the internal temperature and humidity acquisition unit 111 acquires the internal temperature from the internal temperature and humidity measuring device 11.

[0111] Next, in step S6, the first operation mode control unit 131 determines whether or not the internal temperature is higher than a predetermined target temperature.

[0112] If it is determined that the internal temperature is higher than the predetermined target temperature (YES in step S6), then in step S7, the first operation mode control unit 131 determines whether the air conditioner 14 is off. If it is determined that the air conditioner 14 is not off, that is, if it is determined that the air conditioner 14 is on (NO in step S7), the process returns to step S4.

[0113] On the other hand, if it is determined that the air conditioner 14 is in the OFF state (YES in step S7), in step S8, the first operation mode control unit 131 outputs a control signal to the air conditioner 14 to change the air conditioner 14 to the ON state. When the air conditioner 14 receives the control signal, it changes to the ON state. Then, the air conditioner 14 performs cooling operation so that the internal temperature becomes equal to or lower than a predetermined target temperature.

[0114] If it is determined in step S6 that the internal temperature is equal to or lower than the predetermined target temperature (NO in step S6), then in step S9, the first operation mode control unit 131 determines whether the air conditioner 14 is on or not. If it is determined that the air conditioner 14 is not on, that is, if it is determined that the air conditioner 14 is off (NO in step S9), the process returns to step S4.

[0115] On the other hand, if it is determined that the air conditioner 14 is in the ON state (YES in step S9), in step S10, the first operation mode control unit 131 outputs a control signal to the air conditioner 14 to change the air conditioner 14 to the OFF state. When the air conditioner 14 acquires the control signal from the first operation mode control unit 131, it changes the state to the OFF state. Then, the air conditioner 14 stops cooling operation.

[0116] In steps S5 to S10, the target temperature control process of operating the air conditioner 14 so that the internal temperature becomes a predetermined target temperature with the side windows 121 and the skylight 171 closed corresponds to the process in the first operation mode.

[0117] If it is determined in step S4 that the current time is the dew condensation prevention process start time (YES in step S4), in step S11, the second operation mode control unit 132 performs dew condensation prevention process to prevent dew condensation from occurring on the fruit. The dew condensation prevention process corresponds to the process in the second operation mode.

[0118] Here, the dew condensation prevention process in step S11 will be described.

[0119] FIG. 4 is a flowchart for explaining the condensation prevention process in step S11 of FIG.

[0120] First, in step S21, the second operation mode control unit 132 determines whether the current time is the end time of the condensation prevention process. If it is determined that the current time is the end time of the condensation prevention process (YES in step S21), the process proceeds to step S12 in FIG.

[0121] On the other hand, if it is determined that the current time is not the dew condensation prevention process end time (NO in step S21), the fruit surface temperature acquisition unit 112 acquires the fruit surface temperature from the surface temperature measurement device 15 in step S22.

[0122] Next, in step S23, the internal temperature and humidity acquisition unit 111 acquires the internal temperature and internal humidity from the internal temperature and humidity measuring device 11.

[0123] Next, in step S24, the second operation mode control unit 132 calculates the internal dew point temperature of the cultivation facility 100 based on the internal temperature and internal humidity acquired by the internal temperature and humidity acquisition unit 111.

[0124] Next, in step S25, the second operation mode control unit 132 judges whether or not the fruit surface temperature is higher than the internal dew point temperature + α. α is a temperature margin for preventing condensation, for example, 0.5° C. If it is judged that the fruit surface temperature is higher than the internal dew point temperature + α (YES in step S25), in step S26, the second operation mode control unit 132 judges whether or not the air conditioner 14 is on.

[0125] If it is determined here that the air conditioner 14 is not in the ON state, that is, if it is determined that the air conditioner 14 is in the OFF state (NO in step S26), the process returns to step S21.

[0126] On the other hand, if it is determined that the air conditioner 14 is in the ON state (YES in step S26), in step S27, the second operation mode control unit 132 outputs a control signal to the air conditioner 14 to change the air conditioner 14 to the OFF state. Upon receiving the control signal, the air conditioner 14 changes to the OFF state. Then, the air conditioner 14 stops cooling operation.

[0127] If it is determined in step S25 that the fruit surface temperature is equal to or lower than the internal dew point temperature +α (NO in step S25), the second operation mode control unit 132 determines in step S28 whether the air conditioner 14 is in the OFF state. If it is determined that the air conditioner 14 is not in the OFF state, that is, if it is determined that the air conditioner 14 is in the ON state (NO in step S28), the process returns to step S21.

[0128] If it is determined in step S28 that the air conditioner 14 is not in the off state, the second operation mode control unit 132 may perform error processing. In the error processing, the second operation mode control unit 132 may notify the user that the fruit surface temperature does not become higher than the internal dew point temperature even though the air conditioner 14 is in the on state and the cooling operation is being performed.

[0129] On the other hand, if it is determined that the air conditioner 14 is in the OFF state (YES in step S28), in step S29, the second operation mode control unit 132 outputs a control signal to the air conditioner 14 to change the air conditioner 14 to the ON state. When the air conditioner 14 receives the control signal, it changes the state to the ON state. Then, the air conditioner 14 performs cooling operation. When the air conditioner 14 is turned ON and performs cooling operation, the internal humidity of the cultivation facility 100 decreases. As a result, the fruit surface temperature becomes higher than the internal dew point temperature.

[0130] In step S25, the second operation mode control unit 132 determines whether the fruit surface temperature is higher than the internal dew point temperature +α, but the present disclosure is not limited to this, and the second operation mode control unit 132 may compare the fruit surface temperature with a value obtained by adding the error temperature and the temperature margin α to the internal dew point temperature. The error temperature is, for example, 2°C.

[0131] Returning to Fig. 3, next, in step S12, the third operation mode control unit 133 performs a window-opening process to open the side window 121 and the skylight 171. The window-opening process corresponds to the process of the third operation mode.

[0132] Here, the window opening process in step S12 will be described.

[0133] FIG. 5 is a flowchart for explaining the window opening process in step S12 of FIG.

[0134] First, in step S41, the third operation mode control unit 133 determines whether or not the air conditioner 14 is in the ON state. If it is determined that the air conditioner 14 is not in the ON state, that is, if it is determined that the air conditioner 14 is in the OFF state (NO in step S41), the process proceeds to step S43.

[0135] On the other hand, if it is determined that the air conditioner 14 is in the ON state (YES in step S41), in step S42, the third operation mode control unit 133 outputs a control signal to the air conditioner 14 to change the air conditioner 14 to the OFF state. When the air conditioner 14 acquires the control signal from the third operation mode control unit 133, it changes the state to the OFF state. Then, the air conditioner 14 stops cooling operation.

[0136] Next, in step S43, the third operation mode control unit 133 outputs control signals to the side window drive device 12 and the skylight drive device 17 to open the side window 121 and the skylight 171 by 30%. The side window drive device 12 opens the side window 121 by 30% in accordance with the control signal from the third operation mode control unit 133. Also, the skylight drive device 17 opens the skylight 171 by 30% in accordance with the control signal from the third operation mode control unit 133. The third operation mode control unit 133 stores in the memory 102 the time when the side window 121 and the skylight 171 were opened.

[0137] Next, in step S44, the third operation mode control unit 133 judges whether or not a predetermined time has elapsed since the side window 121 and the skylight 171 were opened. The predetermined time is, for example, 30 minutes. If it is judged that the predetermined time has not elapsed since the side window 121 and the skylight 171 were opened (NO in step S44), the judgment process of step S44 is performed until the predetermined time has elapsed since the side window 121 and the skylight 171 were opened.

[0138] On the other hand, if it is determined that the predetermined time has passed since the side window 121 and skylight 171 were opened (YES in step S44), in step S45, the third operation mode control unit 133 outputs control signals to the side window drive device 12 and the skylight drive device 17 to open the side window 121 and the skylight 171 100%. The side window drive device 12 opens the side window 121 100% in accordance with the control signal from the third operation mode control unit 133. Also, the skylight drive device 17 opens the skylight 171 100% in accordance with the control signal from the third operation mode control unit 133.

[0139] Then, after the window opening process in step S12 in FIG. 3 is performed, the temperature control process ends.

[0140] After sunrise, solar radiation enters the cultivation facility 100, causing the internal temperature of the cultivation facility 100 to rise. The temperature of the fruits rises in accordance with the internal temperature of the cultivation facility 100. Then, after a predetermined time has elapsed from sunrise, the air conditioner 14 is stopped, the ventilator fan 13 is operated, and the side windows 121 and skylight 171 are opened. At this time, since the air conditioner 14 continues to operate after sunrise, the internal humidity is kept relatively low, and the internal dew point temperature is also low.

[0141] In this way, at night, the air conditioner 14 operates with the side windows 121 and the skylight 171 closed so that the internal temperature of the cultivation facility 100 becomes a predetermined target temperature. From before sunrise to after sunrise, the air conditioner 14 operates with the side windows 121 and the skylight 171 closed so that the surface temperature of the fruit 10 becomes higher than the internal dew point temperature of the cultivation facility 100. Then, when the internal temperature of the cultivation facility 100 approaches the external temperature of the cultivation facility 100, the air conditioner 14 stops with the side windows 121 and the skylight 171 open. Therefore, when the side windows 121 and the skylight 171 are opened after sunrise, the internal temperature of the cultivation facility 100 approaches the external temperature of the cultivation facility 100 and the surface temperature of the fruit 10 becomes higher than the internal dew point temperature of the cultivation facility 100, so that condensation on the surface of the fruit 10 can be reliably prevented.

[0142] In the first embodiment, the side windows 121 and the skylight 171 are initially opened 30%, but the present disclosure is not particularly limited thereto. The side windows 121 and the skylight 171 may be initially opened 50%, and the proportion at which the side windows 121 and the skylight 171 are initially opened is not particularly limited.

[0143] In addition, in the present embodiment 1, the third operation mode control unit 133 opens the side window 121 and the skylight 171 in two stages, but the present disclosure is not particularly limited to this, and the side window 121 and the skylight 171 may be opened in three or more stages.

[0144] Furthermore, when the cultivation system does not include the side window driving device 12 and the user manually opens the side window 121, the third operation mode control unit 133 may display a screen instructing the user to open the side window 121 by 30% on a display device connected to the temperature control device 1 or a terminal device owned by the user. Then, after a predetermined time has elapsed from the time the side window 121 was opened, the third operation mode control unit 133 may display a screen instructing the user to open the side window 121 by 100% on the display device or terminal device.

[0145] Similarly, when the cultivation system is not equipped with the skylight driving device 17 and the user manually opens the skylight 171, the third operation mode control unit 133 may display a screen on a display device connected to the temperature control device 1 or a terminal device owned by the user instructing the user to open the skylight 171 30%. Then, after a predetermined time has elapsed from the time the skylight 171 was opened, the third operation mode control unit 133 may display a screen on the display device or terminal device instructing the user to open the skylight 171 100%.

[0146] Next, a first modified example of the present embodiment 1 will be described. In the above-described present embodiment 1, in the window-opening process, the third operation mode control unit 133 opens the side window 121 and the skylight 171 in stages, but in the first modified example of the present embodiment 1, in the window-opening process, the third operation mode control unit 133 does not open the side window 121 and the skylight 171 in stages, but opens the side window 121 and the skylight 171 100% at once.

[0147] FIG. 6 is a flowchart illustrating a window opening process according to a first modified example of the first embodiment of the present disclosure.

[0148] The processes in steps S51 and S52 are the same as those in steps S41 and S42 shown in FIG. 5, and therefore will not be described.

[0149] Next, in step S53, the third operation mode control unit 133 outputs a control signal to the side window driving device 12 to fully open the side window 121 and the skylight 171. and skylight drive unit 17The side window driving device 12 fully opens the side window 121 in accordance with a control signal from the third operation mode control unit 133. Furthermore, the skylight driving device 17 fully opens the skylight 171 in accordance with a control signal from the third operation mode control unit 133.

[0150] In addition, if the cultivation system is not equipped with a side window driving device 12 and the user manually opens the side window 121, the third operation mode control unit 133 may display a screen instructing the user to fully open the side window 121 on a display device connected to the temperature control device 1 or on a terminal device owned by the user.

[0151] Similarly, if the cultivation system is not equipped with a skylight driving device 17 and the user manually opens the skylight 171, the third operation mode control unit 133 may display a screen on a display device connected to the temperature control device 1 or on a terminal device owned by the user, instructing the user to fully open the skylight 171.

[0152] Next, a second modified example of the present embodiment 1 will be described. In the above-described present embodiment 1, in step S21 of the dew condensation prevention process, the second operation mode control unit 132 determines whether or not the current time is the dew condensation prevention process end time, but in the second modified example of the present embodiment 1, in the dew condensation prevention process, the second operation mode control unit 132 determines whether or not the internal temperature has reached a growth limit temperature, which is the limit for fruit growth.

[0153] That is, in the above-described first embodiment, the temperature control by the air conditioner 14 is performed even after sunrise. However, after sunrise, the internal temperature of the cultivation facility 100 rises due to irradiation of sunlight even if the temperature control by the air conditioner 14 is performed. Therefore, the second operation mode control unit 132 may transition from the second operation mode to the third operation mode when the internal temperature reaches a limit growth temperature at which the fruit cannot grow. The limit growth temperature is a temperature at which the fruit to be cultivated cannot grow, and is, for example, 30°C.

[0154] FIG. 7 is a flowchart illustrating the condensation prevention process in the second modified example of the first embodiment of the present disclosure.

[0155] First, in step S71, the internal temperature and humidity acquisition unit 111 acquires the internal temperature from the internal temperature and humidity measuring device 11.

[0156] Next, in step S72, the second operation mode control unit 132 judges whether the internal temperature has reached the limit temperature for fruit growth. If it is judged that the internal temperature has reached the limit temperature for fruit growth (YES in step S72), the process proceeds to step S12 in FIG. 3.

[0157] On the other hand, if it is determined that the internal temperature has not reached the growth limit temperature (NO in step S72), the fruit surface temperature acquisition unit 112 acquires the fruit surface temperature from the surface temperature measurement device 15 in step S73.

[0158] The processing from step S73 to step S80 is the same as the processing from step S22 to step S29 shown in FIG. 4, and therefore a description thereof will be omitted.

[0159] (Embodiment 2) In the above-mentioned embodiment 1, the second operation mode control unit 132 transitions from the second operation mode to the third operation mode when the current time is the end time of the condensation prevention treatment, whereas in this embodiment 2, the second operation mode control unit calculates the external dew point temperature of the cultivation facility 100 based on the external temperature and external humidity of the cultivation facility 100, and transitions from the second operation mode to the third operation mode when the surface temperature of the fruit becomes higher than the external dew point temperature.

[0160] FIG. 8 is an overall view showing the configuration of a cultivation system according to the second embodiment of the present disclosure.

[0161] 8 includes a temperature control device 1A, an internal temperature and humidity measuring device 11, a side window driving device 12, a ventilation fan 13, an air conditioner 14, a surface temperature measuring device 15, a skylight driving device 17, a side window 121, a skylight 171, and an external temperature and humidity measuring device 16. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0162] The external temperature and humidity measuring device 16 measures the external temperature and external humidity of the cultivation facility 100. The external temperature and humidity measuring device 16 includes a temperature sensor 161 and a humidity sensor 162. The temperature sensor 161 measures the external temperature of the cultivation facility 100. The humidity sensor 162 measures the external humidity of the cultivation facility 100. The external humidity is the relative humidity outside the cultivation facility 100. The temperature sensor 161 and the humidity sensor 162 are installed at any location outside the cultivation facility 100.

[0163] FIG. 9 is a block diagram showing a configuration of a temperature control device according to the second embodiment of the present disclosure.

[0164] The temperature control device 1A shown in FIG.

[0165] The processor 101A is, for example, a CPU, and includes an internal temperature and humidity acquisition unit 111, a fruit surface temperature acquisition unit 112, a temperature control unit 113A, and an external temperature and humidity acquisition unit 114.

[0166] The external temperature and humidity acquisition unit 114 acquires the external temperature and external humidity of the cultivation facility 100 measured by the external temperature and humidity measuring device 16. The external temperature and humidity acquisition unit 114 periodically acquires the external temperature and external humidity from the external temperature and humidity measuring device 16 at predetermined time intervals.

[0167] The temperature control unit 113A includes a first operation mode control unit 131, a second operation mode control unit 132A, and a third operation mode control unit 133.

[0168] The second operation mode control unit 132A calculates an external dew point temperature of the cultivation facility 100 based on the external temperature and the external humidity. When the surface temperature of the fruit becomes higher than the external dew point temperature, the second operation mode control unit 132A transitions from the second operation mode to the third operation mode.

[0169] The second operation mode control unit 132A calculates the outside dew point temperature based on the following formula (3).

[0170] External dew point temperature = 237.3 * log (external water vapor pressure / 6.11) / (7.5 * log (10) + log (6.11 / external water vapor pressure)) (3) The external water vapor pressure is calculated based on the following formula (4).

[0171] External water vapor pressure = 6.11 * 10^(7.5 * external temperature / (273.3 + external temperature)) * external humidity / 100 · · · (4) When the fruit surface temperature is equal to or lower than the external dew point temperature, the second operation mode control unit 132A operates the air conditioner 14 so that the surface temperature of the fruit 10 becomes higher than the internal dew point temperature with the side window 121 and the skylight 171 closed. When the fruit surface temperature is higher than the external dew point temperature, the second operation mode control unit 132A shifts from the dew condensation prevention process of the second operation mode control unit 132A to the window opening process of the third operation mode control unit 133.

[0172] Other functions of the second operation mode control unit 132A are the same as those of the second operation mode control unit 132 in the first embodiment.

[0173] Next, a description will be given of the temperature control process of the temperature control device 1A in the second embodiment of the present disclosure. The temperature control process of the temperature control device 1A in the second embodiment differs from the temperature control process of the temperature control device 1 in the first embodiment only in the condensation prevention process. Therefore, in the following description, only the condensation prevention process in the second embodiment will be described.

[0174] FIG. 10 is a flowchart illustrating the condensation prevention process according to the second embodiment of the present disclosure.

[0175] First, in step S91, the fruit surface temperature acquisition unit 112 acquires the fruit surface temperature from the surface temperature measurement device 15.

[0176] Next, in step S92, the external temperature and humidity acquisition unit 114 acquires the external temperature and external humidity from the external temperature and humidity measuring device 16.

[0177] Next, in step S93, the second operation mode control unit 132A calculates the external dew point temperature of the cultivation facility 100 based on the external temperature and external humidity acquired by the external temperature and humidity acquisition unit 114.

[0178] Next, in step S94, the second operation mode control unit 132A determines whether the fruit surface temperature is higher than the outside dew point temperature. If it is determined that the fruit surface temperature is higher than the outside dew point temperature (YES in step S94), the process proceeds to step S12 in FIG. 3.

[0179] On the other hand, if it is determined that the fruit surface temperature is equal to or lower than the external dew point temperature (NO in step S94), the fruit surface temperature acquisition unit 112 acquires the fruit surface temperature from the surface temperature measurement device 15 in step S95.

[0180] The process from step S95 to step S102 is the same as the process from step S22 to step S29 shown in FIG. 4, and therefore the description thereof will be omitted.

[0181] In step S98, the second operation mode control unit 132A may determine whether the fruit surface temperature acquired in step S91 is higher than the internal dew point temperature + α. In this case, the fruit surface temperature acquisition unit 112 does not need to acquire the fruit surface temperature from the surface temperature measurement device 15 in step S95.

[0182] In step S94, the second operation mode control unit 132A determines whether the fruit surface temperature is higher than the external dew point temperature, but the present disclosure is not limited to this, and the second operation mode control unit 132A may compare the fruit surface temperature with a value obtained by adding an error temperature to the external dew point temperature. The error temperature is, for example, 2°C.

[0183] Moreover, the temperature control device 1A in the second embodiment may be adapted to the first and second modifications of the first embodiment.

[0184] (Embodiment 3) In the above-mentioned embodiment 1, the cultivation system is equipped with a surface temperature measuring device 15, and the fruit surface temperature acquisition unit 112 acquires the fruit surface temperature measured by the surface temperature measuring device 15, but in this embodiment 3, the cultivation system is not equipped with a surface temperature measuring device 15, and the temperature control device 1B estimates the fruit surface temperature.

[0185] FIG. 11 is an overall diagram showing a configuration of a cultivation system in the third embodiment of the present disclosure, and FIG. 12 is a block diagram showing a configuration of a temperature control device in the third embodiment of the present disclosure.

[0186] 11 includes a temperature control device 1B, an internal temperature and humidity measuring device 11, a side window driving device 12, a ventilation fan 13, an air conditioner 14, a skylight driving device 17, a side window 121, and a skylight 171. In the third embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0187] The cultivation system of the third embodiment differs from the cultivation system of the first embodiment in that the surface temperature measuring device 15 is not provided.

[0188] A temperature control device 1B shown in FIG. 12 includes a processor 101B and a memory 102B.

[0189] The processor 101B is, for example, a CPU, and includes an internal temperature and humidity acquisition unit 111, a temperature control unit 113B, and a fruit surface temperature estimation unit 115.

[0190] Memory 102B stores a surface temperature estimation table that associates the internal temperature of the cultivation facility 100 at the time of transition to the condensation prevention treatment (second operating mode) and the elapsed time from the time of transition to the condensation prevention treatment (second operating mode) with an estimated value of the surface temperature of the fruit.

[0191] FIG. 13 is a diagram illustrating an example of a surface temperature estimation table stored in a memory according to the third embodiment of the present disclosure.

[0192] The surface temperature estimation table associates the internal temperature of the cultivation facility 100 at the time of transition to the condensation prevention treatment, the elapsed time from the time of transition to the condensation prevention treatment, and the estimated value of the fruit surface temperature.

[0193] 13, the top row represents the internal temperature of the cultivation facility 100 at the time of transition to the dew condensation prevention treatment, and the leftmost column represents the elapsed time from the time of transition to the dew condensation prevention treatment. For example, if the internal temperature of the cultivation facility 100 at the time of transition to the dew condensation prevention treatment is 18°C ​​and one hour has elapsed since the time of transition to the dew condensation prevention treatment, the estimated value of the fruit surface temperature is 20°C.

[0194] Moreover, the memory 102B stores the internal temperature of the cultivation facility 100 at the time when the dew condensation prevention process (second operation mode) is started.

[0195] The fruit surface temperature estimation unit 115 estimates the surface temperature of the fruit. The fruit surface temperature estimation unit 115 extracts an estimated value associated with the internal temperature at the time of transition to the dew condensation prevention process (second operation mode) and the elapsed time from the time of transition to the dew condensation prevention process (second operation mode) from a surface temperature estimation table stored in the memory 102B.

[0196] The temperature control unit 113B includes a first operation mode control unit 131, a second operation mode control unit 132B, and a third operation mode control unit 133.

[0197] The second operation mode control unit 132B operates the air conditioner 14 with the side window 121 and the skylight 171 closed so that the estimated value of the surface temperature of the fruit 10 is higher than the internal dew point temperature. That is, when the estimated value of the fruit surface temperature estimated by the fruit surface temperature estimator 115 is higher than the internal dew point temperature and the air conditioner 14 is in the on state, the second operation mode control unit 132B outputs a control signal to the air conditioner 14 to change the air conditioner 14 to the off state. In addition, when the estimated value of the fruit surface temperature is higher than the internal dew point temperature and the air conditioner 14 is in the off state, the second operation mode control unit 132B does not output a control signal to the air conditioner 14. In addition, when the estimated value of the fruit surface temperature is equal to or lower than the internal dew point temperature and the air conditioner 14 is in the off state, the second operation mode control unit 132B outputs a control signal to the air conditioner 14 to change the air conditioner 14 to the on state. Furthermore, the second operation mode control unit 132B does not output a control signal to the air conditioner 14 when the estimated value of the fruit surface temperature is equal to or lower than the internal dew point temperature and the air conditioner 14 is in the on state.

[0198] Other functions of the second operation mode control unit 132B are the same as those of the second operation mode control unit 132 in the first embodiment.

[0199] Next, the temperature control process of the temperature control device 1B in the third embodiment of the present disclosure will be described. The temperature control process of the temperature control device 1B in the third embodiment differs from the temperature control process of the temperature control device 1 in the first embodiment only in the dew condensation prevention process. Therefore, in the following description, only the dew condensation prevention process in the third embodiment will be described.

[0200] FIG. 14 is a flowchart illustrating the condensation prevention process according to the third embodiment of the present disclosure.

[0201] First, in step S111 , the internal temperature and humidity acquisition unit 111 acquires the internal temperature from the internal temperature and humidity measuring device 11 .

[0202] Next, in step S112, the internal temperature and humidity acquisition unit 111 stores the acquired internal temperature in the memory 102B as the internal temperature at the time of transition to the condensation prevention process.

[0203] Next, in step S113, the second operation mode control unit 132B determines whether the current time is the end time of the condensation prevention process. If it is determined that the current time is the end time of the condensation prevention process (YES in step S113), the process proceeds to step S12 in FIG.

[0204] On the other hand, if it is determined that the current time is not the dew condensation prevention process end time (NO in step S113), the fruit surface temperature estimation unit 115 estimates the fruit surface temperature in step S114. The fruit surface temperature estimation unit 115 extracts an estimated value of the fruit surface temperature associated with the internal temperature at the time of transition to the dew condensation prevention process and the elapsed time from the time of transition to the dew condensation prevention process from the surface temperature estimation table stored in memory 102B.

[0205] The processes in steps S115 and S116 are the same as those in steps S23 and S24 shown in FIG. 4, and therefore will not be described.

[0206] Next, in step S117, the second operation mode control unit 132B judges whether the estimated value of the fruit surface temperature is higher than the internal dew point temperature + α. α is a temperature margin for preventing condensation, for example, 0.5° C. If it is judged that the estimated value of the fruit surface temperature is higher than the internal dew point temperature + α (YES in step S117), in step S118, the second operation mode control unit 132B judges whether the air conditioner 14 is on.

[0207] The processes in steps S118 and S119 are the same as those in steps S26 and S27 shown in FIG. 4, and therefore will not be described.

[0208] Also, if it is determined in step S117 that the estimated value of the fruit surface temperature is equal to or lower than the internal dew point temperature +α (NO in step S117), in step S120, the second operation mode control unit 132B determines whether the air conditioner 14 is off or not.

[0209] The processes in steps S120 and S121 are the same as those in steps S28 and S29 shown in FIG. 4, and therefore will not be described.

[0210] Furthermore, if it is determined in step S120 that the air conditioner 14 is not in the OFF state, the second operation mode control unit 132B may perform error processing. In the error processing, the second operation mode control unit 132B may notify the user that the fruit surface temperature does not become higher than the internal dew point temperature even though the air conditioner 14 is in the ON state and the cooling operation is being performed.

[0211] In step S117, the second operation mode control unit 132B determines whether the estimated value of the fruit surface temperature is higher than the internal dew point temperature +α, but the present disclosure is not limited to this, and the second operation mode control unit 132B may compare the estimated value of the fruit surface temperature with a value obtained by adding the error temperature and the temperature margin α to the internal dew point temperature. The error temperature is, for example, 2°C.

[0212] Moreover, the temperature control device 1B in the present embodiment 3 may apply the first and second modified examples of the above-mentioned embodiment 1. Furthermore, the cultivation system in the present embodiment 3 may apply the above-mentioned embodiment 2.

[0213] In the above first to third embodiments, the temperature control method for preventing condensation from forming on the surface of fruit in hot and humid regions has been described, focusing on the time when switching from cooling at night to introducing outside air during the day.

[0214] However, even in areas other than hot and humid areas, when the temperature and humidity around the fruit change during cultivation, the temperature control devices of embodiments 1 to 3 can prevent condensation from occurring on the surface of the fruit by controlling the temperature so that the surface temperature of the fruit is higher than the internal dew point temperature of the cultivation facility 100.

[0215] In addition, in the first to third embodiments, the cultivation system includes the side window 121 and the skylight 171, but the present disclosure is not particularly limited to this, and the cultivation system may include only one of the side window 121 and the skylight 171.

[0216] In each of the above embodiments, each component may be implemented by dedicated hardware or by executing a software program suitable for each component. Each component may be implemented by a program execution unit such as a CPU or processor reading and executing a software program recorded on a recording medium such as a hard disk or semiconductor memory.

[0217] A part or all of the functions of the device according to the embodiment of the present disclosure are typically realized as an LSI (Large Scale Integration), which is an integrated circuit. These may be individually integrated into one chip, or may be integrated into one chip that includes some or all of the functions. The integrated circuit is not limited to an LSI, and may be realized by a dedicated circuit or a general-purpose processor. An FPGA (Field Programmable Gate Array) that can be programmed after the LSI is manufactured, or a reconfigurable processor that can reconfigure the connections and settings of circuit cells inside the LSI, may be used.

[0218] Furthermore, some or all of the functions of the device according to the embodiment of the present disclosure may be realized by a processor such as a CPU executing a program.

[0219] Furthermore, all the numbers used above are merely examples for the purpose of specifically explaining the present disclosure, and the present disclosure is not limited to the numbers exemplified.

[0220] In addition, the order in which each step is performed shown in the above flowchart is merely an example for specifically explaining the present disclosure, and an order other than the above may be used as long as the same effect is obtained. In addition, some of the steps may be performed simultaneously (in parallel) with other steps. [Industrial Applicability]

[0221] INDUSTRIAL APPLICABILITY The technology disclosed herein can reliably prevent condensation from forming on the surface of fruit, and is therefore useful as a technology for controlling the internal temperature of fruit cultivation facilities. [Explanation of symbols]

[0222] 1,1A,1B Temperature control device 10. Fruit 11 Internal temperature and humidity measuring device 12 Side window drive unit 13 Ventilator 14 Air conditioning equipment 15 Surface temperature measuring device 16 External temperature and humidity measuring device 17 Skylight drive unit 100 Cultivation facilities 101, 101A, 101B Processors 102,102B memory 111 Internal temperature and humidity acquisition unit 112 Fruit surface temperature acquisition unit 113, 113A, 113B Temperature control unit 114 External temperature / humidity acquisition section 115 Fruit surface temperature estimation unit 121 Side Window 131 First operation mode control unit 132, 132A, 132B Second operation mode control section 133 Third operation mode control unit 141,161 Temperature Sensors 142,162 Humidity Sensor 171 Skylight

Claims

1. A temperature control method for a temperature control device that controls an internal temperature of a fruit cultivation facility, comprising: Acquire the internal temperature and internal humidity of the cultivation facility; The internal temperature of the cultivation facility is controlled by sequentially switching between a first operation mode, a second operation mode, and a third operation mode; The first operation mode includes operating an air conditioner so that the internal temperature becomes a predetermined target temperature with an openable window separating the inside and the outside of the cultivation facility closed, The second operation mode calculates an internal dew point temperature of the cultivation facility based on the internal temperature and the internal humidity, and operates the air conditioning equipment with the windows closed so that the surface temperature of the fruit is higher than the internal dew point temperature; The third operation mode includes stopping the air conditioner while keeping the window open, In the second operation mode, the surface temperature of the fruit being cultivated is further acquired from a sensor that measures the surface temperature of the fruit being cultivated in a non-contact manner, or the surface temperature of the fruit is estimated. Temperature control method.

2. After a predetermined time has elapsed from sunrise, the second operation mode is switched to the third operation mode. The temperature control method according to claim 1.

3. When the internal temperature reaches a temperature that is a limit for the growth of the fruit, the operation mode is shifted from the second operation mode to the third operation mode. The temperature control method according to claim 1.

4. Furthermore, the external temperature and external humidity of the cultivation facility are acquired, an external dew point temperature of the cultivation facility is calculated based on the external temperature and the external humidity, and when a surface temperature of the fruit becomes higher than the external dew point temperature, the operation mode is switched from the second operation mode to the third operation mode. The temperature control method according to claim 1.

5. extracting the estimated value associated with the internal temperature at the time of transition to the second operation mode and the elapsed time since the time of transition to the second operation mode from a table in which the internal temperature of the cultivation facility at the time of transition to the second operation mode and the elapsed time since the time of transition to the second operation mode are associated with an estimated value of the surface temperature of the fruit; The temperature control method according to claim 1.

6. In the third operation mode, the window is opened stepwise at predetermined time intervals. The temperature control method according to any one of claims 1 to 5.

7. A temperature control device for controlling an internal temperature of a fruit cultivation facility, An acquisition unit that acquires an internal temperature and an internal humidity of the cultivation facility; A control unit that controls the internal temperature of the cultivation facility by sequentially switching between a first operation mode, a second operation mode, and a third operation mode; Equipped with The first operation mode includes operating an air conditioner so that the internal temperature becomes a predetermined target temperature with an openable window separating the inside and the outside of the cultivation facility closed, The second operation mode calculates an internal dew point temperature of the cultivation facility based on the internal temperature and the internal humidity, and operates the air conditioning equipment with the windows closed so that the surface temperature of the fruit is higher than the internal dew point temperature; The third operation mode includes stopping the air conditioner while keeping the window open, In the second operation mode, the surface temperature of the fruit being cultivated is further acquired from a sensor that measures the surface temperature of the fruit being cultivated in a non-contact manner, or the surface temperature of the fruit is estimated. Temperature control device.

8. A temperature control program for controlling an internal temperature of a fruit cultivation facility, comprising: Acquire the internal temperature and internal humidity of the cultivation facility; causing a computer to function to control the internal temperature of the cultivation facility by sequentially switching between a first operating mode, a second operating mode, and a third operating mode; The first operation mode includes operating an air conditioner so that the internal temperature becomes a predetermined target temperature with an openable window separating the inside and the outside of the cultivation facility closed, The second operation mode calculates an internal dew point temperature of the cultivation facility based on the internal temperature and the internal humidity, and operates the air conditioning equipment with the windows closed so that the surface temperature of the fruit is higher than the internal dew point temperature; The third operation mode includes stopping the air conditioner while keeping the window open, In the second operation mode, the surface temperature of the fruit being cultivated is further acquired from a sensor that measures the surface temperature of the fruit being cultivated in a non-contact manner, or the surface temperature of the fruit is estimated. Temperature control program.

9. A temperature control device that controls an internal temperature of the fruit cultivation facility; Air conditioning equipment, An openable window separating the inside and outside of the cultivation facility; Equipped with The temperature control device includes: An acquisition unit that acquires an internal temperature and an internal humidity of the cultivation facility; A control unit that controls the internal temperature of the cultivation facility by sequentially switching between a first operation mode, a second operation mode, and a third operation mode; Equipped with the first operating mode is to operate the air conditioner so that the internal temperature becomes a predetermined target temperature with the window closed; The second operation mode calculates an internal dew point temperature of the cultivation facility based on the internal temperature and the internal humidity, and operates the air conditioning equipment with the windows closed so that the surface temperature of the fruit is higher than the internal dew point temperature; The third operation mode includes stopping the air conditioner while keeping the window open, In the second operation mode, the surface temperature of the fruit being cultivated is further acquired from a sensor that measures the surface temperature of the fruit being cultivated in a non-contact manner, or the surface temperature of the fruit is estimated. Temperature control system.

10. A temperature control method for a temperature control device that controls an internal temperature of a fruit cultivation facility, comprising: acquiring a surface temperature of the fruit during cultivation from a sensor that non-contactly measures the surface temperature of the fruit during cultivation; The internal temperature of the cultivation facility is controlled by sequentially switching between a first operation mode, a second operation mode, and a third operation mode; The first operation mode includes operating an air conditioner so that the internal temperature becomes a predetermined target temperature with an openable window separating the inside and the outside of the cultivation facility closed, The second operation mode calculates an internal dew point temperature of the cultivation facility based on the internal temperature and the internal humidity, and operates the air conditioning equipment with the windows closed so that the surface temperature of the fruit is higher than the internal dew point temperature; The third operation mode includes stopping the air conditioner with the window open. Temperature control method.

11. A temperature control device for controlling an internal temperature of a fruit cultivation facility, an acquisition unit that acquires a surface temperature of the fruit during cultivation from a sensor that measures the surface temperature of the fruit during cultivation in a non-contact manner; A control unit that controls the internal temperature of the cultivation facility by sequentially switching between a first operation mode, a second operation mode, and a third operation mode; Equipped with The first operation mode includes operating an air conditioner so that the internal temperature becomes a predetermined target temperature with an openable window separating the inside and the outside of the cultivation facility closed, The second operation mode calculates an internal dew point temperature of the cultivation facility based on the internal temperature and the internal humidity, and operates the air conditioning equipment with the windows closed so that the surface temperature of the fruit is higher than the internal dew point temperature; The third operation mode includes stopping the air conditioner with the window open. Temperature control device.

12. A temperature control program for controlling an internal temperature of a fruit cultivation facility, comprising: acquiring a surface temperature of the fruit during cultivation from a sensor that non-contactly measures the surface temperature of the fruit during cultivation; causing a computer to function to control the internal temperature of the cultivation facility by sequentially switching between a first operating mode, a second operating mode, and a third operating mode; The first operation mode includes operating an air conditioner so that the internal temperature becomes a predetermined target temperature with an openable window separating the inside and the outside of the cultivation facility closed, The second operation mode calculates an internal dew point temperature of the cultivation facility based on the internal temperature and the internal humidity, and operates the air conditioning equipment with the windows closed so that the surface temperature of the fruit is higher than the internal dew point temperature; The third operation mode includes stopping the air conditioner with the window open. Temperature control program.

13. A temperature control device that controls an internal temperature of the fruit cultivation facility; Air conditioning equipment, An openable window separating the inside and outside of the cultivation facility; A sensor for non-contactly measuring the surface temperature of the fruit during cultivation; Equipped with The temperature control device includes: an acquisition unit that acquires a surface temperature of the fruit being cultivated from the sensor; A control unit that controls the internal temperature of the cultivation facility by sequentially switching between a first operation mode, a second operation mode, and a third operation mode; Equipped with the first operating mode is to operate the air conditioner so that the internal temperature becomes a predetermined target temperature with the window closed; The second operation mode calculates an internal dew point temperature of the cultivation facility based on the internal temperature and the internal humidity, and operates the air conditioning equipment with the windows closed so that the surface temperature of the fruit is higher than the internal dew point temperature; The third operation mode includes stopping the air conditioner with the window open. Temperature control system.

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