JP7112063B2 - Gas supply device and plant cultivation system - Google Patents

Description

The present disclosure relates to gas supply devices and plant cultivation systems.

BACKGROUND ART In plant cultivation systems for growing plants, attempts have been made to adjust conditions such as temperature and carbon dioxide concentration so as to be suitable for growing plants. For example, Patent Document 1 proposes a technique of recovering and storing carbon dioxide from combustion exhaust gas generated by a heater in order to warm the inside of an agricultural house at night, and applying it to the inside of an agricultural house during the day. there is In this technique, an adsorbent such as activated carbon or zeolite is used as means for recovering carbon dioxide.

Patent Literature 2 proposes a plant cultivation apparatus including an air conditioner that adjusts air supplied to a housing having a space for cultivating plants to conditions corresponding to the cultivation of plants. The temperature, humidity and _CO2 concentration of the air are regulated by placing a cooling blower, a _CO2 adder and a humidifier in the air conditioner. The _CO2 adder discharges _CO2 when the _CO2 concentration in the enclosure decreases due to plant photosynthesis. On the other hand, a humidifier sprays mist when the plants do not photosynthesize and the stomata are closed to reduce the amount of transpiration to compensate for the humidity.

JP 2015-126708 A JP 2017-205072 A

FIG. 17 shows an example of changes over time in the concentration of carbon dioxide, relative humidity, and temperature in a greenhouse when using a gas supply device using fossil fuel combustion gas, which is provided in a conventional plant cultivation system. As shown in FIG. 17, when the combustion gas is introduced into the greenhouse during the daytime when photosynthesis takes place, the temperature rises and the relative humidity drops. Here, in order to create an environment suitable for plant growth, if not only the concentration of carbon dioxide but also the relative humidity are adjusted, providing individual adjustment mechanisms would complicate the configuration of the device.

Therefore, in one aspect, an object of the present disclosure is to provide a plant cultivation gas supply apparatus capable of supplying gas suitable for a plant growth environment with a simple apparatus configuration. In another aspect, an object of the present disclosure is to provide a plant cultivation system that is equipped with the gas supply device described above, thereby promoting the growth of plants and simplifying the equipment configuration.

In one aspect, the present disclosure provides a storage section containing a material that reversibly absorbs and releases carbon dioxide and water according to their partial pressures, and a first storage section containing carbon dioxide and water. a gas introduction unit for switchably introducing a gas and a second gas having a carbon dioxide partial pressure lower than that of the first gas; and a gas discharge part for discharging a third gas having a high concentration of carbon dioxide and a high relative humidity.

In the gas supply device of the present disclosure, a material that reversibly absorbs and releases carbon dioxide and water according to their respective partial pressures is stored in the storage part. This material releases carbon dioxide and water absorbed during the introduction of the first gas during the introduction of the second gas into the container. The gas discharge unit discharges a third gas having a carbon dioxide concentration and relative humidity higher than those of the second gas, for example, during a time period when plants perform photosynthesis. By supplying such a third gas to the cultivating section for cultivating plants, the concentration of carbon dioxide and the relative humidity can be increased as compared with the case where the second gas is directly supplied to the cultivating section.

Generally, when the photosynthesis of plants becomes active, the plants in the cultivation section absorb carbon dioxide. At this time, in order for the plant to efficiently take in carbon dioxide into the leaves, it is necessary to suppress the decrease in the relative humidity in order to increase the opening of the stomata of the leaves. The gas supply device described above can increase the relative humidity as well as the concentration of carbon dioxide, thereby further promoting photosynthesis. In addition, since the material stored in the storage portion is used to absorb and release carbon dioxide and water, the configuration of the device can be simplified. In this way, it is possible to supply a gas (third gas) suitable for the growing environment of plants with a simple device configuration.

In addition, during the entire period during which the second gas is introduced from the gas introduction part, the third gas having a carbon dioxide concentration and relative humidity higher than those of the second gas is continuously discharged from the gas discharge part. is not required. For example, immediately after the introduction gas from the gas introduction part is switched from the first gas to the second gas, or when the second gas is continuously introduced for a long period of time, all the carbon dioxide and water absorbed by the material are After being discharged, the gas discharge section may discharge a gas different from the third gas (for example, a gas having the same carbon dioxide concentration and relative humidity as the second gas).

The gas discharge part may discharge a fourth gas having a carbon dioxide partial pressure lower than that of the first gas while the first gas is being introduced from the gas introduction part. This allows efficient absorption of carbon dioxide by the material. It should be noted that it is not necessary to continuously discharge the fourth gas from the gas discharge part during the entire period during which the first gas is being introduced from the gas introduction part. For example, immediately after the introduction gas from the gas introduction part is switched from the second gas to the first gas, and the introduction of the first gas is continued for a long period of time, the upper limit of the amount of carbon dioxide and water absorbed by the material After reaching , the gas discharge unit may discharge a gas different from the fourth gas (for example, a gas having the same carbon dioxide concentration and relative humidity as the first gas).

A humidity control unit for controlling the humidity of the material may be provided. This facilitates the material's ability to absorb and release water while maintaining its performance at a sufficiently high level. Therefore, the growth of plants can be further promoted. Also, the frequency of material replacement can be reduced.

A liquid discharge part for discharging a liquid containing water from the storage part may be provided. As a result, it is possible to prevent the material stored in the storage unit from being clogged with condensed water or the like caused by dew condensation, thereby reducing the performance of the material.

Water from the liquid outlet may be used to condition the material. This can reduce water consumption.

The materials may be contained in one or more cartridges mounted in the receptacles. This facilitates exchange of materials.

At least some of the plurality of cartridges may be replaced at different times. This allows, for example, a portion whose material is likely to deteriorate to be replaced more frequently than a portion whose material is less likely to deteriorate. Compared to the case where all the materials are replaced each time, it is possible to reduce the cost while reducing the load of the replacement work.

The first gas is combustion gas containing oxidizing components of at least one of NOx and SOx, and the material absorbs at least part of the oxidizing components and is introduced from the gas introduction portion. Alternatively, the amount of the oxidizing component discharged from the gas discharge portion may be reduced. This can reduce the concentration and release of oxidizing components.

In another aspect, the present disclosure provides a plant comprising any one of the gas supply devices described above, and a cultivation section having an internal space in which a plant is cultivated and gas is supplied to the internal space from the gas supply device. Provide a cultivation system. Since such a plant cultivation system is provided with the above-described gas supply device, it is possible to simplify the equipment configuration while promoting the growth of plants.

The plant cultivation system includes a first measuring unit that measures the amount of light irradiated to the plant, and a first measuring unit that adjusts the concentration and relative humidity of carbon dioxide in the internal space of the cultivation unit based on the signal from the first measuring unit. and a control unit. This makes it possible, for example, to adjust the carbon dioxide concentration and relative humidity in time with the start and stop of photosynthesis by plants. Therefore, it is possible to further promote the growth of plants by reducing the time lag between the initiation and termination of photosynthesis and their regulation.

The plant cultivation system includes a second measuring unit that measures at least one of the carbon dioxide concentration and relative humidity in the internal space, and the concentration of carbon dioxide in the internal space of the cultivating unit and the and a second controller that adjusts at least one of the relative humidity. By providing the second measurement section and the second control section, the carbon dioxide concentration and relative humidity can be adjusted with higher accuracy. Therefore, the growth of plants can be further promoted.

In one aspect, the present disclosure can provide a plant cultivation gas supply apparatus capable of supplying gas suitable for a plant growth environment with a simple apparatus configuration. In another aspect, the present disclosure can provide a plant cultivation system that facilitates the growth of plants and that can simplify the facility configuration by including the gas supply device.

FIG. 1 is a schematic diagram showing one embodiment of the gas supply device. FIG. 2 is a diagram showing the operation of the gas supply device and the plant cultivation system in the absorption mode. FIG. 3 is a diagram showing operation of the gas supply device and the plant cultivation system in the release mode. FIG. 4 is a diagram showing an example of temporal changes in temperature, relative humidity, and carbon dioxide concentration in a cultivation section. FIG. 5 is a diagram showing an example of how materials are stored in the storage section. FIG. 6 is a functional block diagram showing an example of control applied to the plant cultivation system. FIG. 7 is a schematic diagram of the gas supply apparatus of Examples 1 and 2. FIG. 8 is a photograph of the acrylic plate used in Examples 1 and 2. FIG. 9 is a photograph of the lid of the acrylic container used in Examples 1 and 2. FIG. 10 is a photograph of the acrylic container body used in Examples 1 and 2. FIG. 11 is a graph showing temporal changes in the amount of carbon dioxide absorbed and released in Example 1. FIG. 12 is a graph showing temporal changes in carbon dioxide concentration and relative humidity in Example 1. FIG. 13 is a graph showing temporal changes in the amount of carbon dioxide absorbed and released in Example 2. FIG. 14 is a graph showing temporal changes in carbon dioxide concentration and relative humidity in Example 2. FIG. 15 is a graph showing integrated values of carbon dioxide absorption amounts in Examples 1 and 2. FIG. FIG. 16 is a graph showing integrated values of the amount of carbon dioxide released in Examples 1 and 2; FIG. 17 is a diagram showing an example of temporal changes in temperature, relative humidity, and carbon dioxide concentration in a conventional cultivation section.

An embodiment of the present invention will be described below with reference to the drawings as the case may be. However, the following embodiments are examples for explaining the present invention, and are not intended to limit the present invention to the following contents. In the description, the same reference numerals are used for the same elements or elements having the same function, and overlapping descriptions are omitted in some cases. In addition, unless otherwise specified, positional relationships such as up, down, left, and right are based on the positional relationships shown in the drawings. Furthermore, the dimensional ratio of each element is not limited to the illustrated ratio.

FIG. 1 is a schematic diagram showing an embodiment of a gas supply device for plant cultivation. The gas supply device 100 shown in FIG. and a second gas having a carbon dioxide partial pressure lower than that of the first gas; While the first gas is introduced into the storage section 12 from the gas discharge section 16a that discharges the third gas having a carbon dioxide concentration and relative humidity higher than those of the second gas, and the gas introduction section 14 , and a gas discharge portion 16b for discharging a fourth gas having a carbon dioxide partial pressure and relative humidity lower than those of the first gas. The gas discharge portion 16a and the gas discharge portion 16b may be collectively referred to as the gas discharge portion 16 in some cases.

The gas introduction section 14 is connected to, for example, a heating section. The heating unit burns a fossil fuel such as heavy oil or kerosene to generate a combustion gas having a higher temperature than the introduced gas and a high carbon dioxide concentration from the introduced gas such as air. The gas introduction part 14 introduces the combustion gas as the first gas and the introduction gas such as air as the second gas into the accommodation part 12 in a switchable manner. A filter for removing fine particles such as soot contained in the combustion gas may be provided at or near the gas introduction part 14 . Also, a blower, a fan, or a compressor may be arranged at or near the gas introduction section 14 . Thereby, the combustion gas or air can be efficiently introduced into the housing portion 12 .

The material 10 contained in the reservoir 12 can be of various types capable of reversibly absorbing and releasing carbon dioxide and water through pressure swings that change the partial pressure of carbon dioxide and/or the partial pressure of water. can be used. In addition to reversible absorption and release of carbon dioxide and water, the amount of absorption and release of each of carbon dioxide and water can also be controlled by pressure that changes the partial pressure of carbon dioxide and/or the partial pressure of water. It can also be adjusted by swing.

Components contained in the material 10 include polymer gels, polymer gel fine particles, aggregates of polymer gel fine particles, porous polymer gels, anion exchange resins, and the like. Polymer gels, polymer gel fine particles, aggregates of polymer gel fine particles, and porous polymer gels may be polymers of monomers having amino groups. Monomers include N-(aminoalkyl)acrylamides. The anion exchange resin may be a weakly basic anion exchange resin having tertiary amines as exchange groups. Specifically, acrylic WA10, styrene WA20 series, styrene WA30, etc. (all trade names) manufactured by Mitsubishi Chemical Co., Ltd., and WMT-7624LG, Dowex 66, and Marathon WBA manufactured by Muromachi Chemical Co., Ltd. (both are trade names) can be used. The material 10 may contain moisture from the viewpoint of performance maintenance. The water content in the material 10 may be, for example, 1-95% by weight.

The first gas may be combustion gas containing oxidizing components of at least one of NOx and SOx. In this case, the material 10 absorbs at least a part of the oxidizing components and reduces the amount of oxidizing components discharged from the gas discharge part 16 as compared with the amount of oxidizing components introduced from the gas introduction part 14. may be This can reduce the concentration and release of oxidizing components. Also, if the first gas has carbon monoxide and odors, material 10 may not absorb carbon monoxide and odors. In this case, carbon monoxide and odor may be discharged from the gas discharge part 16b as components contained in the fourth gas. Thus, the gas supply device 100 can constitute a clean environmental control system.

The gas supply device 100 has at least two modes of operation including, for example, an absorption mode in which the material 10 absorbs carbon dioxide and a release mode in which the material 10 releases carbon dioxide. Hereinafter, the configuration of the gas supply device 100 and the plant cultivation system 200 including the same will be described in detail using each mode as an example.

FIG. 2 is a diagram showing operations of the gas supply device 100 and the plant cultivation system 200 in the absorption mode. The plant cultivation system 200 includes a gas supply device 100 and a cultivation section 50 having an internal space 52 in which plants are grown and gas is supplied from the gas supply device 100 to the internal space 52 . Plants are cultivated in the cultivation unit 50 . Plants are not limited as long as they perform photosynthesis, and may be agricultural crops such as vegetables and grains, or may be flowers, algae, and plants.

In the absorption mode, the heating unit 30 burns fuel containing hydrocarbons supplied from the burner 32 in air to generate a first gas containing carbon dioxide and water. The concentration of carbon dioxide in the first gas may be, for example, 1% by volume or more, 2 to 30% by volume, or 5 to 20% by volume. The gas volume ratio in the present disclosure is the volume ratio under standard conditions (0° C., 1 atm).

All or a part of the first gas generated in the heating section 30 flows toward the gas introduction section 14 through a channel 34 branching from a channel 33 toward the chimney. A blower, a fan, a compressor, or the like may be provided in the flow path 34 in order to efficiently introduce the first gas into the gas introduction section 14 . Moreover, the flow path 34 may be provided with a cooler, a filter, a thermometer, a hygrometer, or the like. The temperature of the first gas introduced from the gas introduction section 14 into the storage section 12 is, for example, 5 to 50.degree.

A humidity control unit 40 is connected to the flow path 34 . The humidity control section 40 may humidify or dehumidify the first gas continuously or intermittently. This allows the material 10 to be maintained at a humidity that readily absorbs water. In addition, the humidity can be set to sufficiently suppress deterioration in the performance of the material 10 due to drying. The humidity control unit 40 may be, for example, a spray type one in which water is atomized and merged with the first gas, or may be an ultrasonic atomizer. The first gas may be introduced into the housing portion 12 together with water mist, for example. In some other embodiments, the humidity control unit may humidify the first gas by bubbling it in water. It is not essential to provide the humidity control section on the upstream side of the gas introduction section 14 . For example, it may be connected to the storage section 12 and the water from the humidity control section 40 may be sprayed onto the material 10 . The humidity control section may include a thermometer and a hygrometer, and a mechanism for controlling the water temperature and the humidity of the first gas during humidity control. The first gas to be introduced can be cooled or controlled to an appropriate temperature by controlling the cooling effect of evaporation and water temperature.

The first gas that has flowed through the flow path 34 is introduced from the gas introduction section 14 into the storage section 12 . The pressure (absolute pressure) of the first gas introduced into the housing portion 12 may be, for example, 100 to 1000 kPa, 100 to 200 kPa, or 100 to 150 kPa. The partial pressure of carbon dioxide in the first gas may be, for example, 0.1-200 kPa, 0.25-40 kPa, or 2-20 kPa. The partial pressure of water in the first gas may be greater than 0 and 100 kPa, and may be 1 to 50 kPa.

The first gas introduced into the containing portion 12 from the gas introducing portion 14 contacts the material 10 contained in the containing portion 12 . The material 10 absorbs carbon dioxide and water contained in the first gas. At this time, the material 10 may absorb gaseous water or liquid water. In the absorption mode, the gas outlet 16a is closed and the gas outlet 16b is open. A fourth gas having a carbon dioxide partial pressure lower than that of the first gas is discharged from the gas discharge portion 16b. The fourth gas may be discharged to the atmosphere as it is from the gas discharge part 16b, or may be discharged to the atmosphere after being purified. Moreover, when the fourth gas is at a high temperature, heat recovery may be performed. The temperature of the fourth gas is, for example, 10-50.degree. When the concentration of carbon dioxide in the fourth gas is higher than the concentration of carbon dioxide in the cultivation unit 50, the gas discharge unit 16a is opened, the gas discharge unit 16b is closed, and carbon dioxide is absorbed by the material 10. Alternatively, a fourth gas containing carbon dioxide may be supplied to the cultivation section 50 .

The absorption mode shown in FIG. 2 is performed, for example, at night when photosynthesis of plants is not performed. Since photosynthesis does not occur at night, the growth of the plants is not hindered even if the gas is not supplied from the gas supply device 100 to the cultivation section 50 where the plants are cultivated. In addition, the cultivation unit 50 is, for example, a greenhouse. However, the cultivation section 50 is not limited to a vinyl house, and may be a plant factory provided in a building. The plant factory may have a lighting device to facilitate plant photosynthesis. In such a case, the absorption mode can be performed during a period of time when no light is emitted from the illumination device.

FIG. 3 is a diagram showing operation of the gas supply device 100 and the plant cultivation system 200 in the release mode. In emission mode, combustion in heating section 30 is stopped. As a result, the second gas having a carbon dioxide partial pressure lower than that of the first gas is introduced from the gas introduction part 14 into the storage part 12 . The partial pressure of water in the second gas may be lower than the partial pressure of water in the first gas. The second gas is air, for example. As the second gas, for example, air may be introduced from the outside air via the heating unit 30, or the internal space 52 of the cultivation unit 50 and the flow path 34 or the gas introduction unit 14 may be connected to the gas in the internal space 52. may be introduced. The second gas may be a gas having a higher concentration of carbon dioxide than air. This makes it possible to further increase the concentration of carbon dioxide in the third gas. The pressure (absolute pressure) of the second gas introduced into the housing portion 12 is, for example, 100 to 200 kPa.

When the second gas is introduced from the gas introduction part 14 into the storage part 12 and the second gas comes into contact with the material 10, carbon dioxide and water absorbed in the material 10 are released. In the release mode, gas outlet 16b is closed and gas outlet 16a is open. A third gas having a carbon dioxide concentration and relative humidity higher than those of the second gas is discharged from the gas discharge portion 16a. This third gas is discharged from the gas discharge section 16 a and supplied to the cultivation section 50 . When the second gas is air, in the release mode, the cultivation unit 50 is supplied with the third gas having a carbon dioxide concentration and relative humidity higher than those of air.

The carbon dioxide concentration and relative humidity of the third gas discharged from the gas discharge portion 16b may change over time. The concentration of carbon dioxide in the third gas may be, for example, 0.1 to 20% by volume, or 0.2 to 5% by volume. The relative humidity of the third gas may be, for example, 30% RH or higher, and may be 50 to 98% RH. On the other hand, the concentration of carbon dioxide in the second gas introduced from the gas introduction section 14 may be, for example, less than 1% by volume. The relative humidity of the second gas may be, for example, 80% RH or less, and may be 5 to 40% RH.

The emission mode shown in FIG. 3 is performed, for example, during the daytime when photosynthesis of plants takes place. In this mode, the third gas having a higher carbon dioxide concentration and relative humidity than the second gas (for example, air) is supplied from the gas supply device 100 to the cultivation section 50 where plants are grown. Since the third gas has a higher relative humidity than the second gas, it is possible to increase the opening of the stomata on the leaf surface of the plant. In addition, since the third gas has a higher concentration of carbon dioxide than the second gas, the carbon dioxide can be effectively absorbed by plants. In this way, plant growth can be promoted.

As the water contained in the material 10 evaporates, the temperature of the third gas may become lower than the temperature of the second gas. As a result, for example, an excessive temperature rise in the internal space 52 of the cultivation section 50 during the daytime is suppressed, and the frequency of ventilation can be reduced. As a result, the outflow of carbon dioxide into the atmosphere can be reduced, and the rate of carbon dioxide consumption by photosynthesis can be sufficiently increased to effectively utilize carbon dioxide. The temperature of the second gas in the gas introduction section 14 is, for example, 40° C. or lower, and the temperature of the third gas in the gas discharge section 16a is, for example, 38° C. or lower.

In the release mode, water may be continuously or intermittently added to the third gas from the humidity control unit 40 to adjust the humidity of the third gas, as in the absorption mode, or the humidity may not be adjusted. By controlling the temperature of the third gas or water using a cooling device or a heating device, the third gas can be more effectively conditioned. When the cultivating section 50 is in a plant factory provided in a building, the carbon dioxide release mode can be performed during a time zone when the plants are illuminated with light from the lighting device.

FIG. 4 is a diagram showing an example of temporal changes in the concentration of carbon dioxide, temperature, and relative humidity in the internal space 52 of the cultivation unit 50. As shown in FIG. The gas supply device 100 operates in the absorption mode shown in FIG. 2 at night. Therefore, the third gas is not supplied to the internal space 52 of the cultivation section 50 . At sunrise when photosynthesis of plants begins, the gas supply device 100 starts operating in the release mode shown in FIG. After starting the operation in the release mode, a third gas having a carbon dioxide concentration and relative humidity higher than those of the second gas (air) is introduced into the internal space 52 of the cultivation unit 50 . This increases the concentration of carbon dioxide and the relative humidity in the interior space 52 . Therefore, the photosynthesis of the plants in the internal space 52 becomes active and the growth is promoted.

The temperature of the internal space 52 also rises due to sunlight, for example. Since the temperature of the third gas discharged from the gas discharge part 16a is lower than the temperature of the second gas introduced from the gas introduction part 14, the temperature rise of the internal space 52 is suppressed. Therefore, an excessive temperature rise in the internal space 52 is suppressed. As a result, the frequency of ventilation in the cultivation section 50 is reduced, and the concentration and humidity of carbon dioxide in the internal space 52 can be maintained high.

In FIG. 4, R and A indicate an example of the time zones of emission mode and absorption mode. In this example, the operation mode of the gas supply device 100 is switched from the release mode to the absorption mode as the time of sunset at which photosynthesis becomes less active approaches. After switching, the concentration of carbon dioxide and the relative humidity in the internal space 52 gradually decrease due to photosynthesis of plants. After sunset, plants stop photosynthesizing, and changes in carbon dioxide concentration and relative humidity become smaller. Note that the concentration of carbon dioxide, the relative humidity, and the temperature in the internal space 52 may fluctuate even after sunset due to the effects of ventilation, temperature fluctuations, and the like.

In the example of FIG. 4, the mode is switched from the absorption mode to the emission mode at sunrise and then from the emission mode to the absorption mode before sunset, but the present invention is not limited to this. In another example, the absorption mode may be switched to the emission mode before sunrise to increase the concentration of carbon dioxide and relative humidity in the interior space 52 before sunrise. It is also possible to switch from the absorption mode to the emission mode to increase the carbon dioxide concentration and relative humidity in the interior space 52 after sunrise as the carbon dioxide concentration and relative humidity in the interior space 52 begin to decline. . In yet another example, the emission mode may be switched to the absorption mode at sunset. Alternatively, the emission mode may be switched to the absorption mode after sunset. In yet another example, when the absorption and release amounts of carbon dioxide and water are small compared to the size of the internal space 52 of the cultivation unit 50, and it is difficult to continuously release carbon dioxide and water during the daytime. Alternatively, the emission mode may be operated intermittently or intermittently during the daytime, or the absorption mode and the emission mode may be alternately operated during the daytime.

FIG. 5 is a diagram showing an example of how materials are stored in the storage section 12. As shown in FIG. The material 10 is contained in a plurality of cartridges 11a, 11b, 11c, 11d, and 11e (hereinafter also referred to as "cartridges 11a to 11e") mounted in the container 12. As shown in FIG. The accommodating portion 12 includes a holding portion 18 that holds the cartridges 11a to 11e. The replaceable cartridges 11a to 11e are held by the holding portion 18 and mounted in the accommodating portion 12. As shown in FIG. The holding part 18 may be, for example, a plate-shaped mesh-like member.

The cartridges 11a-11e may in one example consist of a honeycomb and the material attached to the honeycomb. In another example, it may be a molded body in which a mixture of plastic and material is molded. In another example, the material may be supported on a filter such as a non-woven fabric. Since the material 10 may deteriorate due to oxidation, making the material 10 easy to replace is extremely useful in practice.

The material 10 absorbs and releases carbon dioxide and water in a reversible manner according to their respective partial pressures, but there are cases where the performance deteriorates depending on the state of use and the like, requiring replacement. At this time, the cartridges 11a to 11e may all be replaced at the same time, or at least some of the cartridges 11a to 11e may be replaced at different times.

For example, if the combustion gas generated by the heating unit 30 contains soot or the like, the performance of the cartridge 11a, which is arranged furthest upstream, tends to deteriorate fastest among the cartridges 11a to 11e. In such a case, only the cartridge 11a may be replaced. Only the cartridges 11a and 11b may be replaced depending on the state of performance deterioration. Although five cartridges are mounted in this example, the number of cartridges may be one. Material exchange can be facilitated by using a cartridge that is attached to the container.

The housing portion 12 is provided with a liquid discharge portion 60 for discharging liquid including water from the interior of the housing portion 12 . The liquid discharged from the liquid discharge section may include condensed water generated as the temperature of the gas introduced into the storage section 12 is lowered, water mist added by the humidity control section 40, and the like. By providing the gas supply device 100 with the liquid discharge part 60, it is possible to prevent the material contained in the containing part from clogging with water and lowering the performance.

The liquid containing water discharged from the liquid discharge part 60 may be used for moistening the material. For example, a flow path connecting the liquid discharge section 60 and the humidity control section 40 may be provided, and the liquid may be used in the humidity control section 40 . A liquid pump may be installed in the channel connecting the liquid discharge section 60 and the humidity control section 40 to efficiently circulate water.

FIG. 6 is a functional block diagram showing an example of control applied to the plant cultivation system 200. As shown in FIG. In this example, a light intensity measurement unit 54 (first measurement unit) that measures the amount of light irradiated to the plant in the cultivation unit 50, a first control unit 72 to which a signal from the light intensity measurement unit 54 is input, and the cultivation unit 50 A carbon dioxide concentration measurement unit 56 (second measurement unit) that measures the concentration of carbon dioxide in the internal space 52, a relative humidity measurement unit 58 that measures the relative humidity of the internal space 52, a carbon dioxide concentration measurement unit 56, and a relative A second control section 74 to which a signal from the humidity measurement section 58 is input is provided.

Based on the signal from the light amount measuring unit 54, the first control unit 72 determines whether the concentration of carbon dioxide and the relative humidity in the internal space 52 of the cultivation unit need to be adjusted. Then, when it is determined that the amount of light tends to increase, it outputs a first control signal for increasing the concentration of carbon dioxide and the relative humidity. On the other hand, when it is determined that the amount of light tends to decrease, it outputs a first control signal for decreasing the concentration of carbon dioxide and the relative humidity.

The second control unit 74 generates a second control signal for adjusting the carbon dioxide concentration and relative humidity in the internal space 52 of the cultivation unit 50 based on the signals from the carbon dioxide concentration measurement unit 56 and the relative humidity measurement unit 58. Calculate The control by the second control unit 74 may be configured to be able to perform normal PID control processing (P: proportional control, I: integral control, D: derivative control). The first control signal and the second control signal are input to the adding section 76 .

The adder 76 adds the first control signal and the second control signal and outputs the result to the adjuster 80 . The adjustment unit 80 adjusts, for example, the introduction amount of the second gas introduced from the gas introduction unit 14 to the storage unit 12 based on the input signal from the addition unit 76, so that the carbon dioxide in the internal space 52 of the cultivation unit 50 concentration and relative humidity. The introduction amount of the second gas may be adjusted by using a flow control valve, or by adjusting the air volume of a blower provided upstream of the heating section 30 or near the gas introduction section 14 .

By combining the feedforward control by the first control unit 72 and the feedback control by the second control unit 74 as shown in FIG. is possible, and the growth of plants can be further promoted. In addition, the control applied to the plant cultivation system 200 is not limited to the form shown in FIG. may be performed only by feedback control. Alternatively, the same control may be performed by measuring only one of carbon dioxide and relative humidity without measuring both.

The first control unit 72, the second control unit 74, and the addition unit 76 may be configured as separate hardware, or may be configured to function by common hardware. The first control unit 72, the second control unit 74, and the addition unit 76 may include, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an input/output interface, and the like. .

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. For example, although the gas supply device 100 has one gas introduction part 14, the gas introduction part 14 may be divided into two, one for the first gas and one for the second gas. Further, for example, although the gas supply device 100 has two gas discharge units, the discharge of the third gas and the discharge of the fourth gas may be performed in common, and one gas discharge unit may be provided. In this case, on the downstream side of the gas discharge section connected to the storage section 12, the pipe may be branched so that the flow paths of the third gas and the fourth gas are separated. Moreover, it is not essential to mount the cartridge in the accommodating portion, and for example, the accommodating portion itself may be configured to be replaceable.

The gas delivery device may have modes of operation other than absorption and release modes. For example, when photosynthesis is not active, such as when it is cloudy, the supply of the third gas to the cultivation section is stopped by stopping the introduction of the second gas to the storage section without continuously performing the release mode. You may also perform a stop mode to Also, between the absorption mode and the release mode, a hydration mode may be performed in which the material absorbs water. In this case, water may be supplied from the humidity control section 40 .

In the release mode, when the residual amount of carbon dioxide stored in the material 10 decreases and the concentration of carbon dioxide in the third gas decreases, or when the amount of carbon dioxide supplied to the cultivation unit 50 is increased. Or, when it is necessary to raise the temperature of the internal space 52 of the cultivation unit 50, the exhaust gas generated by burning the fossil fuel in the heating unit 30 is passed through the flow path 34, the gas introduction unit 14, and the storage unit 12. Then, an operation mode (combustion mode) in which the fuel is introduced into the cultivation unit 50 may be performed. Further, it is not essential to perform the control as shown in FIG. 6, and manual operation may be performed without performing automatic control.

The content of the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.

(Example 1)
Air gas cylinders G1, G3, carbon dioxide gas cylinder G2, mass flow controllers F1, F2, mass flow meters M1, M2, humidity control unit 40A, thermostat 90, reactor R1, thermometer T1, hygrometer H1, gas chromatography (GC) , a CO ₂ meter, and valves V1 to V10 were connected via pipes to prepare a gas supply apparatus as shown in FIG.

A blank measurement was first carried out in the reactor R1 without installing any material that absorbs and releases carbon dioxide and water. After that, the material was installed according to the following procedure.

A commercially available weakly basic anion exchange resin (substrate: acrylic, trade name: WA10, manufactured by Mitsubishi Chemical Corporation) was suspended in an aqueous NaOH solution (1N) and stirred for 30 minutes. The content of the weakly basic anion exchange resin in the suspension was 30% by mass. After filtering the suspension with a Kiriyama funnel, the solid content was washed with ultrapure water. After washing, 10 g of the solid content was weighed and cast on an acrylic plate (104 mm x 500 mm x 15 mm) having grooves for gas passages to mold the weakly basic anion exchange resin into a predetermined pattern. This acrylic plate was housed in a box-shaped acrylic container to form a reactor R1.

FIG. 8 shows a photograph of the acrylic plate before casting, and FIGS. 9 and 10 show photographs of the acrylic container lid and container body, respectively.

In addition to installing the reactor R1, the valve is set as follows, the humidified gas A containing 10% by volume of carbon dioxide is circulated in the reactor R1, and the weakly basic anion exchange resin in the reactor R1 was allowed to absorb _CO2 .
Open valves: valves V1, V2, V4, V6, V7, V10
Shut-off valves: valves V3, V5, V8, V9

The humidified gas A was passed through the reactor R1 at a flow rate of 80 mL/min for 100 minutes to allow the weakly basic anion exchange resin to absorb carbon dioxide. After that, the valves V1 and V2 were closed and the valve V3 was opened to switch the gas introduced into the reactor R1 to the humidified gas B of air. While the humidified gas B was passed through the reactor R1 at a flow rate of 80 mL/min, carbon dioxide and water were released from the weakly basic anion exchange resin. The release time was arbitrary. After that, in the same manner, the introduction of humidified gas A and humidified gas B was alternately repeated several times. The temperature of the constant temperature bath 90 was kept constant at 30°C.

Based on the _CO2 concentration measured by the _CO2 meter, the _CO2 absorption and release per gram of the weakly basic anion exchange resin were determined. Here, the CO ₂ concentration was corrected using the result of blank measurement performed in advance to eliminate the influence of the time required for gas replacement in the gas supply device and the change in concentration accompanying gas switching.

11 is a graph showing changes over time in the amount of carbon dioxide absorbed and released per 1 g of the weakly basic anion exchange resin of Example 1. FIG. A positive value on the vertical axis of FIG. 11 indicates that carbon dioxide is being released, and a negative value indicates that carbon dioxide is being absorbed. 12 is a graph showing changes over time in carbon dioxide concentration and relative humidity at the outlet of reactor R1 in Example 1. FIG. As shown in FIG. 11, it was confirmed that the weakly basic anion exchange resin hardly deteriorated in performance even after repeated carbon dioxide absorption and release. As shown in FIG. 12, the humidity at the outlet of reactor R1 was maintained above 90%.

(Example 2)
In the same manner as in Example 1, except that the valves V4, V6, and V7 were closed and the valves V5 and V8 were opened, the humidity control unit 40A was not used. The absorption of carbon and the release of carbon dioxide and water from the weakly basic anion exchange resin were repeated. As in Example 1, the _CO2 absorption and release per gram of the weakly basic anion exchange resin were determined based on the _CO2 concentration measured by the _CO2 meter.

13 is a graph showing changes over time in the amount of carbon dioxide absorbed and released per 1 g of the weakly basic anion exchange resin of Example 2. FIG. A positive value on the vertical axis of FIG. 13 indicates that carbon dioxide is being released, and a negative value indicates that carbon dioxide is being absorbed. FIG. 14 is a graph showing changes over time in carbon dioxide concentration and relative humidity at the outlet of reactor R1 in Example 2; As shown in FIG. 13, it was confirmed that the performance of the weakly basic anion exchange resin deteriorated slightly when carbon dioxide absorption and release were repeated. As shown in FIG. 14, it was confirmed that the humidity at the outlet of the reactor R1 tends to decrease as the number of repetitions of carbon dioxide absorption and release increases. This indicates that the amount of water contained in the weakly basic anion exchange resin decreases when the humidity control section is not used, which is a factor in the deterioration of performance.

15 is a graph showing integrated values of carbon dioxide absorption amounts in Examples 1 and 2. FIG. FIG. 16 is a graph showing integrated values of the amount of carbon dioxide released in Examples 1 and 2; From these results, it was also confirmed that the use of the humidity control section can maintain the performance of the weakly basic anion exchange resin at a high level over a long period of time. However, in the case of Example 2 as well, it goes without saying that by increasing the exchange frequency of the weakly basic anion exchange resin, for example, it is possible to supply a gas suitable for the growing environment of plants with a simple apparatus configuration. stomach.

ADVANTAGE OF THE INVENTION According to this indication, the gas supply apparatus for plant cultivation which can supply the gas suitable for the growth environment of a plant with a simple apparatus structure is provided. In addition, by including the gas supply device, a plant cultivation system is provided that facilitates the growth of plants while simplifying the equipment configuration.

DESCRIPTION OF SYMBOLS 10... Material 11a, 11b, 11c, 11d, 11e... Cartridge, 12... Storage part, 14... Gas introduction part, 16, 16a, 16b... Gas discharge part, 18... Holding part, 30... Heating part, 32... Burner , 34... Flow path, 40, 40A... Humidity control unit, 50... Cultivation unit, 52... Internal space, 54... Light amount measurement unit, 56... Carbon dioxide concentration measurement unit, 58... Relative humidity measurement unit, 60... Liquid discharge unit , 72... First control unit, 74... Second control unit, 76... Addition unit, 80... Adjustment unit, 90... Constant temperature bath, 100... Gas supply device, 200... Plant cultivation system.

Claims (11)

a storage unit that stores a material that reversibly absorbs and releases carbon dioxide and water according to their respective partial pressures;
a gas introduction unit for switchably introducing a first gas containing carbon dioxide and water and a second gas having a lower partial pressure of carbon dioxide than the first gas into the storage unit;
a gas discharge unit that discharges a third gas having a higher carbon dioxide concentration and relative humidity than the second gas while the second gas is being introduced from the gas introduction unit ;
When the first gas is introduced from the gas introduction part into the storage part, the material absorbs water and carbon dioxide contained in the first gas,
A gas supply device for cultivating plants , wherein the material releases carbon dioxide and water when the second gas is introduced from the gas introduction part into the storage part . 2. The gas supply device according to claim 1, wherein the gas discharge part discharges a fourth gas having a carbon dioxide partial pressure lower than that of the first gas while the first gas is being introduced from the gas introduction part. 3. The gas supply device according to claim 1, further comprising a humidity control section for controlling the humidity of said material. 4. The gas supply device according to any one of claims 1 to 3, further comprising a liquid discharge section for discharging liquid containing water from the storage section. 5. The gas supply device according to claim 4, wherein water from the liquid discharge part is used for humidity conditioning of the material. a container containing a material that reversibly absorbs and releases carbon dioxide and water according to their respective partial pressures;
a gas introduction unit for switchably introducing a first gas containing carbon dioxide and water and a second gas having a lower partial pressure of carbon dioxide than the first gas into the storage unit;
a gas discharge part for discharging a third gas having a carbon dioxide concentration and relative humidity higher than those of the second gas while the second gas is being introduced from the gas introduction part;
a liquid discharge part for discharging a liquid containing water from the storage part,
A gas supply device for plant cultivation, wherein water from a liquid discharge part is used for humidity conditioning of the material. The gas supply device according to any one of claims 1 to 6 , wherein the material is contained in one or more cartridges attached to the container. the first gas is a combustion gas containing oxidizing components of at least one of NOx and SOx;
3. The material absorbs at least part of the oxidizing component, and reduces the amount of the oxidizing component discharged from the gas discharge part as compared with the amount of the oxidizing component introduced from the gas introduction part. 8. The gas supply device according to any one of 1 to 7. a gas supply device according to any one of claims 1 to 8;
A plant cultivating system comprising: a cultivating unit having an internal space in which a plant is grown, to which gas is supplied from a gas supply device to the internal space. a first measuring unit that measures the amount of light irradiated to the plant;
The plant cultivation system according to claim 9, further comprising a first controller that adjusts the concentration of carbon dioxide and the relative humidity in the inner space of the cultivation section based on the signal from the first measurement section. a second measuring unit that measures at least one of the concentration of carbon dioxide and the relative humidity in the internal space;
The plant cultivation system according to claim 9 or 10, further comprising a second control unit that adjusts at least one of the concentration of carbon dioxide and the relative humidity in the internal space of the cultivation unit based on the signal from the second measurement unit. .

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