Closed house

Abstract

To provide a closed house in which the temperature and humidity are stable throughout the year.SOLUTION: The temperature and humidity in a house are adjusted using a total heat exchanger. In a total heat exchange mode, air in the house is subjected to total heat exchange with the outside air to lower the temperature and humidity. In a dehumidification mode, the air in the house is dehumidified to lower the humidity. By switching between the two operation modes, the environment in the house can be adjusted to the optimum temperature and humidity for plants throughout the year.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a closed house that can maintain stable temperature and humidity throughout the year by simply switching the operation mode of a total heat exchanger.

Background Art

[0002] In agricultural greenhouses for tomatoes, strawberries, etc. (hereinafter, including plant factories, horticultural facilities, etc., referred to as "greenhouses"), the temperature inside the greenhouse often exceeds 30°C (hereinafter, all temperatures are in "degrees Celsius") due to direct sunlight. Therefore, usually on sunny days, the entrances and exits, skylights, sides, etc. of the greenhouse are opened to take in outside air to lower the temperature and humidity inside the greenhouse and create an appropriate cultivation environment. From spring to autumn, the greenhouse is mostly open during the day. However, opening the greenhouse changes the air environment inside the greenhouse, which is stressful for plants. In addition, opening the greenhouse greatly increases the risk of pests and diseases entering from the outside.

[0003] In greenhouse cultivation, photosynthesis is promoted and the yield is improved by maintaining the carbon dioxide concentration higher than that of the atmosphere. For this purpose, carbon dioxide application from a carbon dioxide supply device such as a carbon dioxide cylinder or a combustor such as a kerosene burner is carried out. However, there is a problem that the carbon dioxide supplied by opening the greenhouse is mixed with the outside air and thinned, and the carbon dioxide concentration does not increase, that is, most of the supplied carbon dioxide is released into the atmosphere.

[0004] Therefore, by making the house a closed system without opening it, that is, a completely closed house (hereinafter referred to as a "closed house") or a semi-closed house (semi-closed house), the internal environment such as light, temperature, humidity, and carbon dioxide is controlled to produce plants. Usually, environmental control such as temperature and humidity inside the house is performed using an air conditioner or a dehumidifier. In addition, a method of supplying outside air that has exchanged heat with the air inside the house into the house is also used. Furthermore, when it is desired to actively lower the temperature and humidity, cooling is performed with a heat pump or the like. However, the temperature inside the house easily reaches 30°C or higher under direct sunlight, and cooling with a heat pump or the like requires a very large amount of energy. In addition, since a large amount of dehumidification is required for humidity due to irrigation and transpiration from plants, there is also a problem that the power consumption increases.

[0005] Therefore, in Patent Document 1, a humidity control system is disclosed that can supply carbon dioxide recovered from this air into a closed space and can stabilize the humidity in the closed space even when the outside air is highly humid. This humidity control system includes an adsorption / desorption device (corresponding to the carbon dioxide supply device of the present invention) and a humidity control device (corresponding to the total heat exchanger of the present invention). The adsorption / desorption device adsorbs carbon dioxide and moisture in the air under a first condition and desorbs them under a second condition, a regeneration device that regenerates at least a part of the adsorbent, a first discharge part that discharges a first gas containing the desorbed carbon dioxide and moisture, and a second discharge part that discharges a second gas from which carbon dioxide and moisture have been removed. The humidity control device is configured to have a first air passage through which the first gas passes, a second air passage through which a low-humidity gas containing less moisture than the first gas passes, a moisture permeable membrane that partitions the first air passage and the second air passage and allows moisture to permeate between the first gas and the low-humidity gas.

[0006] In addition, the present inventors proposed in a prior application (Japanese Patent Application No. 2023-063461) a system in which a carbon dioxide supply device is provided in a house, the air in the house is circulated by the carbon dioxide supply device, and the air in the house is totally heat-exchanged with outside air by a total heat exchanger and then supplied back into the house, so that the environment in the house can be adjusted to optimal temperature and humidity for plants without opening the house. This system can utilize carbon dioxide recovered from the atmosphere by DAC (Direct Air Capture) technology for adjusting the carbon dioxide concentration and contributes to carbon neutrality.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] However, when applying the system according to this prior application (Japanese Patent Application No. 2023-063461) to a cold region with a high latitude where house cultivation is prosperous, if the air in the house is totally heat-exchanged with outside air by a total heat exchanger, the temperature in the house will drop extremely in winter because the outside air temperature is too low. Also, in winter, the inside of the house becomes highly humid due to irrigation and transpiration from plants, but since the house cannot be opened or totally heat-exchanged with outside air, it was necessary to install a dehumidifier inside the house.

[0009] Here, if the humidity control system of Patent Document 1 is applied in winter in a cold region with a high latitude, since the outside air temperature is too low in winter, the temperature inside the house may drop extremely, the renewable energy may increase, or it may not be practical. Since the humidity control system of Patent Document 1 supplies the gas (first gas) that has passed through the regeneration section of the adsorption / desorption device directly to the moisture permeation device and then into the house, it is difficult to individually control the supply amount of carbon dioxide and the temperature and humidity inside the house. When individual control is desired, an additional moisture permeation device is required, resulting in problems such as an increase in the initial cost and installation space of the equipment.

[0010] Therefore, the present invention was made to solve this problem. By changing only the operation method of the total heat exchanger in winter, the total heat exchange operation is performed from spring to summer to adjust the temperature and humidity inside the house, and in winter, the dehumidification operation is performed to dehumidify the air inside the house without lowering the temperature, thereby realizing a closed house with stable temperature and humidity throughout the year.

Means for Solving the Problem

[0011] The closed house of the present invention adjusts the temperature and humidity inside the house using a total heat exchanger. In the total heat exchange mode, the air inside the house is subjected to total heat exchange with the outside air to lower the temperature and humidity, and in the dehumidification mode, the air inside the house is dehumidified to lower the humidity. The most important feature is that by switching between these two operation modes, the environment inside the house can be adjusted to the optimal temperature and humidity for plants throughout the year.

Effect of the Invention

[0012] According to the present invention, by switching between the total heat exchange function and the desiccant (dehumidification) function using only a total heat exchanger, a closed house can be realized in which the optimal environment inside the house is stably maintained throughout the year. By using a total heat exchange rotor, the operation mode can be easily switched simply by changing the rotation speed. Since it only consumes the power of the blower of the total heat exchanger and the motor for rotating the rotor, it results in significant energy savings compared to cooling by a heat pump, etc.

[0013] The dehumidification mode of the total heat exchanger used in the present invention is particularly effective in cold regions where the outside air temperature in winter often drops below freezing. In the present invention, the regeneration inlet temperature may be equal to or lower than the treatment inlet temperature. The heat exchanger for heating the outside air in winter does not require high-level heating, and not only warm water but also groundwater, circulating water, solar heat, and geothermal heat can be used as the regeneration heat, which is extremely energy-saving. The present invention is particularly effective in cold (subarctic) regions among regions with four seasons such as Canada, the United States, and Hokkaido.

[0014] Since the closed house of the present invention circulates the air inside the house and does not take in outside air, the carbon dioxide concentration inside the house can be increased to about 800 - 1000 ppm that promotes the photosynthesis of plants by the carbon dioxide supply device. Since there is no leakage of carbon dioxide to the outside air, only the amount of carbon dioxide absorbed by the plants needs to be supplied, and the operation of the carbon dioxide supply device can be minimized, enabling energy-saving operation.

[0015] When the house is a closed system, the air flow becomes weak. Even if the stomata of the leaves are open, the photosynthesis is suppressed because the carbon dioxide concentration near the leaf surface decreases. However, the total heat exchanger can create an air flow inside the house, making it possible to promote the photosynthesis of the leaves. Also, due to the air flow, it is possible to make the temperature, humidity, and carbon dioxide concentration inside the house uniform. In this way, by making the house a closed house, air control such as temperature, humidity, carbon dioxide concentration, and air flow can be realized, providing a space that is less likely to stress plants.

[0016] In addition, windows, motors, etc. for opening the ceiling and sides of the house are not required or can be reduced, so not only the initial cost of the house itself can be suppressed, but also there is an advantage of increased light intake. By making the house a closed system, the influence of wind and rain can be completely blocked. Moreover, since pests and diseases do not enter from the outside, the trouble of setting up insect-proof nets can be saved, and the amount of pesticides can be reduced, making it possible to realize environmentally friendly agriculture such as organic farming.

[0017] The closed house of the present invention can realize a closed house not only for a newly constructed house but also for connecting to an existing house by connecting a cultivation room and a total heat exchange unit with a corridor or a duct. Further, by separating and installing the carbon dioxide supply device and the total heat exchanger separately, it becomes easier to individually control the carbon dioxide concentration and the temperature and humidity in the house. The present invention can be implemented by simply installing a total heat exchanger in a house where a carbon dioxide supply device is installed.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0019] The closed house of the present invention is provided with a carbon dioxide supply device in the house, and the carbon dioxide supply device makes the carbon dioxide concentration of the air in the house higher than that of the outside air, and is provided with a total heat exchanger that performs total heat exchange between the air in the house and the outside air, so that the environment in the house can be adjusted to the optimum temperature and humidity for plants.

[0020] (Closed house) As shown in Fig. 1, the closed house of the present invention is provided with a carbon dioxide supply device 2 and a total heat exchanger 3. The interior of the house 1 is controlled to maintain a certain environment suitable for plant growth, for example, at a temperature of 20 to 30 °C, a humidity of 55 to 85% RH, and a carbon dioxide concentration of 800 to 1000 ppm. The carbon dioxide supply device 2 can increase the carbon dioxide concentration in the house 1 by supplying air with an increased carbon dioxide concentration into the house 1. As a result, it becomes possible to make it about 1000 ppm, which promotes the photosynthesis of plants. The total heat exchanger 3 performs total heat exchange between the air in the house 1 and the outside air and supplies it back into the house 1 again. Thereby, the temperature and humidity of the air in the house 1 where the temperature and humidity have increased are lowered, and the carbon dioxide concentration in the house is not reduced. In this way, the closed house of the present invention can adjust the environment in the house to the optimal temperature and humidity for plants without opening the house.

[0021] (Carbon dioxide supply device) The carbon dioxide supply device used in the closed house of the present invention is not limited, but as shown in Fig. 1, a device that separates, recovers, and concentrates carbon dioxide in the atmosphere by DAC technology using an adsorption rotor 4 and supplies it to plants is preferable. The carbon dioxide supply device 2 takes in the air in the house 1 with a carbon dioxide concentration higher than that of the outside air, and by supplying the air with an even higher carbon dioxide concentration back into the house 1, the carbon dioxide concentration in the house 1 can be increased. In Fig. 1, a carbon dioxide supply device 2 equipped with an adsorption rotor 4 is installed in the house 1. This adsorption rotor 4 is a honeycomb rotor obtained by corrugating (rippling) a non-combustible sheet such as glass fiber or ceramic fiber paper and winding it into a rotor shape, and a carbon dioxide adsorbent such as a weakly basic ion exchange resin or an amine-supported solid adsorbent is supported thereon. Alternatively, this adsorption rotor 4 has a hollow cylindrical shape, and is filled with a granular or pelletized carbon dioxide adsorbent inside.

[0022] The adsorption rotor 4 is rotationally driven at a constant speed around the central axis by a geared motor (not shown) or the like. The adsorption rotor 4 has an adsorption zone that adsorbs carbon dioxide in the outside air through at least the outside air in the rotation direction of the rotor and exhausts it outside the apparatus, and a desorption zone that desorbs the carbon dioxide adsorbed in the adsorption zone through the air heated by a regeneration heater (not shown) or the like in the house 1 and returns it into the house 1. Thereby, the carbon dioxide concentration device 2 concentrates the carbon dioxide in the house 1 and circulates and supplies high-concentration carbon dioxide into the closed house 1. Note that the adsorption rotor 4 may have other zones such as a purge zone and a prepurge zone in addition to the adsorption zone and the desorption zone. Further, the desorption of carbon dioxide from the adsorption rotor 4 is not limited to temperature swing by heating, and may be pressure swing by depressurization.

[0023] The carbon dioxide supply device 2 is not limited to using an adsorption rotor, and a carbon dioxide cylinder, a combustor such as kerosene, or the like may be used. Further, a carbon dioxide supply device using a chemical absorption method, a physical absorption method, a membrane separation method, or the like may be used. By doing so, the present invention can be implemented by simply installing the total heat exchanger described below in a house where a carbon dioxide supply device is already installed.

[0024] (Total heat exchanger) The total heat exchanger 3 used in the closed house of the present invention is such that a part of the air in the house 1 is sent to the total heat exchanger 3 and totally heat-exchanged with the outside air, and then returned to the house 1 again. Thereby, the temperature and humidity of the air in the house 1 where the temperature and humidity have become high are lowered, and the carbon dioxide concentration in the house is not reduced.

[0025] The total heat exchanger 3 includes a total heat exchange rotor 5, and the total heat exchange rotor 5 is formed in a honeycomb shape with an aluminum sheet or the like, a moisture adsorbent is supported on the sheet, and finally formed into a rotatable rotor shape. Examples of the moisture adsorbent include calcium chloride, diatomaceous earth, silica gel, zeolite, ion exchange resin, and polymer adsorbent.

[0026] This total heat exchange rotor 5 has an outside air ventilation zone that exhausts outside air to the outside of the apparatus through the outside air in the rotation direction of the rotor, and an indoor air ventilation zone that returns the air back into the house 1 through the air in the house 1. The total heat exchanger 3 is not limited to the total heat exchange rotor, and other total heat exchangers such as a stationary cross-flow total heat exchanger may be used. Also, a stationary indirect evaporation cooler as shown in Japanese Patent Application Laid-Open No. 10-311691 may be used to lower the temperature. After using the total heat exchanger, it may be combined with a heat pump unit or an evaporation cooler.

[0027] In FIG. 1, the carbon dioxide supply device 2 is installed inside the house 1 and the total heat exchanger 3 is installed outside the house 1, but it is not limited to this, and both may be configured to be installed inside or outside the house 1. Also, the carbon dioxide supply device 2 and the total heat exchanger 3 may be installed between the inside and outside of the house 1, with the adsorption zone of the carbon dioxide supply device 2 on the outside of the house 1 and the desorption zone on the inside of the house 1, and the outside air ventilation zone of the total heat exchanger 3 on the outside of the house 1 and the indoor air ventilation zone on the inside of the house 1. In this way, the ducts connecting the carbon dioxide supply device 2, the total heat exchanger 3, and the house 1 can be eliminated. However, when installing in a cold region, it is preferable to install the device indoors such as inside the house to prevent freezing.

[0028] Note that an integrated device (unit) combining the carbon dioxide supply device 2 and the total heat exchanger 3 as shown in FIG. 2 may also be used. In this case, the entire device becomes compact, but since the air volumes processed by the carbon dioxide supply device and the total heat exchanger are significantly different, it becomes difficult to separately control the carbon dioxide concentration and the temperature and humidity inside the house.

[0029] In the control of the carbon dioxide concentration by the carbon dioxide supply device 2 inside the house and the control of the temperature and humidity by the total heat exchanger 3, the air volume processed by the total heat exchanger is overwhelmingly large. Therefore, it is preferable to separate and install the carbon dioxide supply device 2 and the total heat exchanger 3 as shown in FIG. 1 because it becomes easier to individually control the carbon dioxide supply concentration and the temperature and humidity inside the house.

[0030] In FIG. 1, one carbon dioxide supply device 2 and one total heat exchanger 3 are installed, but the present invention is not limited thereto, and either one or both of them may be installed in multiple units. For example, when the house 1 is large, or when the temperature rise or humidity increase inside the house 1 is large, if it is attempted to cover the temperature and humidity adjustment with a single total heat exchanger, the rotor diameter and the like will increase, and the device will need to be enlarged. However, by using multiple devices, each device can be miniaturized while providing redundancy, which is effective when there is a problem with the installation space of the device.

[0031] Hereinafter, assuming that the closed house of the present invention is applied to a cold region, the operation of the total heat exchanger will be described. In this specification, the "cold region" refers to the cold (subarctic) region among regions with high latitudes and four seasons such as Hokkaido. The cold (subarctic) region belongs to the D climate in the Koppen climate classification, and refers to a region where the average temperature of the coldest month is less than -3°C and the average temperature of the warmest month is 10°C or higher, and is generally distributed from latitude 40 degrees to 70 degrees.

[0032] FIG. 3 shows a flow diagram of the total heat exchanger used in the closed house of the present invention. Similar to FIG. 1, the total heat exchange rotor 5 has a processing zone 6 (indoor air ventilation zone) and a regeneration zone 7 (outdoor air ventilation zone). The total heat exchanger of the present invention has two operating modes: a total heat exchange mode and a dehumidification mode. During spring to autumn, it operates in the total heat exchange mode to adjust the temperature and humidity inside the house, and during winter, it operates in the dehumidification mode to dehumidify without lowering the temperature inside the house, thereby realizing a closed house with stable temperature and humidity throughout the year.

[0033] (Spring - Autumn: Total Heat Exchange Mode) During spring to autumn, the temperature inside the house rises due to solar radiation, and the humidity inside the house rises due to watering or transpiration of plants. Therefore, in the total heat exchange mode, the total heat exchange rotor is operated at a high speed of several tens of rpm (rotations per minute, the number of rotor rotations per minute), for example, 16 - 20 rpm, to perform total heat exchange between the air inside the house and the outdoor air to lower the temperature and humidity.

[0034] On the processing side, a part of the air in the house 1 is sent by the blower 8 through the air filter (AF) to the processing zone 6 (indoor air ventilation zone) of the total heat exchange rotor 5, and undergoes total heat exchange with the outside air in the total heat exchange rotor 5. The air that has passed through the processing zone 6 and has had its temperature and humidity reduced is supplied back into the house 1. On the regeneration side, the outside air is sent by the blower 9 through the air filter to the regeneration zone 7 (outside air ventilation zone) of the total heat exchange rotor 5, and undergoes total heat exchange with the air in the house 1. The air that has passed through the regeneration zone 7 and has had its temperature and humidity increased is exhausted outside the device. In the total heat exchange mode, the heat exchanger 10 provided in front of the regeneration zone 7 is not used.

Example

[0035] Fig. 4 shows the changes in the temperature, humidity, and carbon dioxide concentration inside the house when the total heat exchanger in the closed house according to Example 1 of the present invention is operated in the total heat exchange mode. As shown in Fig. 1, the carbon dioxide supply device 2 and the total heat exchanger 3 were installed separately. During the test, the supply of carbon dioxide from the carbon dioxide supply device was continuously carried out. When the skylight was opened and the house was in an open state (from 9:00 to 11:30), outside air was taken in, but the temperature and humidity inside the house repeated increases and decreases and gradually rose gently. Also, the carbon dioxide concentration ranged from 600 to 800 ppm and gradually decreased. On the other hand, after the skylight was closed and the total heat exchanger was operated to make it a closed house (after 11:30), the increases and decreases in temperature and humidity were eliminated and became almost constant, and gradually decreased. Also, the carbon dioxide concentration maintained a high concentration of 700 to 1000 ppm.

[0036] (Winter: Dehumidification mode) In winter, since the solar radiation is weak, the temperature inside the house hardly rises compared to spring to autumn. However, the humidity inside the house increases due to irrigation and transpiration of plants. The outside air temperature in cold regions often drops below freezing, and in the operation of the total heat exchange mode, cold air is sent into the house, causing the temperature inside the house to drop extremely. Therefore, in the dehumidification mode, the total heat exchange rotor rotates at a low speed of several to several tens of rph (rotations per hour, the number of rotor rotations per hour), for example, 10 to 50 rph, and the dehumidified air is supplied into the house to reduce only the humidity without lowering the temperature inside the house.

[0037] On the processing side, a part of the air in the house 1 passes through the air filter by the blower 8 and is sent to the processing zone 6 (indoor air ventilation zone) of the total heat exchange rotor 5, where it is dehumidified by the total heat exchange rotor 5. The air that has passed through the processing zone 6 and has its humidity reduced is supplied back into the house 1. On the regeneration side, the outside air passes through the air filter by the blower 9 and is sent to a heat exchanger 10 such as a hot water coil to be heated. The air that has passed through the heat exchanger 10 is sent to the regeneration zone 7 (outside air ventilation zone) of the total heat exchange rotor 5 to be humidified, and the air with increased humidity is exhausted outside the device.

[0038] In winter in cold regions, the outside air temperature often drops below freezing, and the temperature inside the house is also lowered under the influence of the outside air. Therefore, heating equipment such as oil heaters and heat pump air conditioners, or the use of hot spring heat or geothermal energy may be used to raise the temperature inside the house. However, due to the recent fuel price hikes, the use of heating equipment is on a downward trend. By using the closed house of the present invention, in winter, it is not affected by the outside air temperature, the air inside the house is recycled, the processing outlet temperature also rises slightly due to the adsorption heat, and the temperature inside the house is not lowered. Therefore, the heating load can be reduced, and it is energy-saving.

Example

[0039] Hereinafter, the operation of the total heat exchanger used in the closed house of the present invention according to Example 2 will be described. In the total heat exchanger of FIG. 3, the estimated results of operating the total heat exchange rotor 5 in the total heat exchange mode from spring to autumn and the dehumidification mode in winter are shown in Table 1. Note that the symbols in Table 1 correspond to the states of the air at the positions of the numbers with parentheses in FIG. 3.

[0040]

Table 1

[0041] During spring to autumn, the total heat exchange rotor 5 operates in the total heat exchange mode. On the processing side, the air (4) inside the house with a high temperature and high humidity of 30.0°C in temperature and 21.6 g / kg (DA) in absolute humidity is heated to 33.0°C by the blower 8 and becomes air (5). This air passes through the processing zone 6 of the total heat exchange rotor 5, undergoes total heat exchange with the outside air, and becomes air (6) with its temperature and humidity reduced to 23.9°C in temperature and 12.6 g / kg (DA) in absolute humidity, and then is returned to the house again. On the regeneration side, the outside air (1) with a temperature of 20.0°C and an absolute humidity of 8.7 g / kg (DA) passes through the regeneration zone 7 by the blower 9 and undergoes total heat exchange with the air inside the house, and becomes air (3) with its temperature and humidity increased to 29.2°C in temperature and 17.7 g / kg (DA) in absolute humidity. Then, the air that exits the blower 9 is exhausted outside the device.

[0042] During winter, the total heat exchange rotor 5 operates in the dehumidification mode. On the processing side, the air (4) inside the house with a temperature of 20.0°C, an absolute humidity of 11.7 g / kg (DA), and a relative humidity of 80% RH, after exiting the blower 8, passes through the processing zone 6 of the total heat exchange rotor 5, where the moisture is adsorbed and the temperature rises due to the heat of adsorption, and becomes dehumidified air (6) with a temperature of 22.5°C and an absolute humidity of 10.7 g / kg (DA). This dehumidified air is returned to the house again. On the regeneration side, the outside air (1) with a low temperature and low humidity of -5.0°C in temperature and 2.1 g / kg (DA) in absolute humidity is heated to 5.0°C by the heat exchanger 10 and its relative humidity is reduced to 38.7% RH, and then enters the regeneration zone 7. The air that passes through the regeneration zone 7 drops to 2.5°C due to the heat of desorption, and its humidity rises to 3.1 g / kg (DA) in absolute humidity and becomes air (3). Then, the air that exits the blower 9 is exhausted outside the device.

[0043] The characteristics of the closed house of the present invention are as follows. During spring to autumn, by operating the total heat exchanger in the total heat exchange mode, the air inside the house is subjected to total heat exchange with the outside air and then returned to the house again, so that in addition to being able to adjust the temperature and humidity inside the house, during winter, by operating in the dehumidification mode, the air inside the house can be dehumidified and the humidity can be adjusted without lowering the temperature inside the house. In this way, by simply switching the operation mode of the total heat exchanger, a stable closed house can be realized throughout the year, and plant production can be carried out in a stable internal environment. If a total heat exchange rotor is used in the total heat exchanger, it is possible to switch the operation mode only by adjusting the rotation speed.

[0044] In normal dehumidification, generally in winter, since the indoor is dry, the humidified air that has passed through the regeneration zone is supplied indoors, and the dehumidified air that has passed through the treatment zone is exhausted. However, the present invention uses the completely opposite idea of dehumidifying the indoor (inside the house).

[0045] A further characteristic of the closed house of the present invention is that in winter in cold regions, the dehumidification mode of the total heat exchanger is extremely effective. Also, the point of the present invention lies in the low temperature range that is generally not used as the regeneration inlet temperature in the winter dehumidification mode. Usually, in temperature swing adsorption using a honeycomb rotor, the operation is carried out with a low temperature on the treatment inlet side and a high temperature on the regeneration inlet side. The regeneration inlet temperature is 40 to 80°C even in low temperature regeneration, and since it is no longer practical when it is 20°C or lower, it is not regarded. The inventors focused on the use of the total heat exchanger and made elaborate efforts to solve the dilemma that the outside air in cold regions in winter is extremely low in humidity and extremely low in temperature, and that there is almost no temperature rise in the house during the day but the humidity rises.

[0046] In Example 2, the heat exchanger 10 raises the temperature of outside air at -5°C and 80%RH to 5°C, thereby reducing the relative humidity on the regeneration inlet side to 38.7%RH and creating a humidity difference with respect to 80%RH on the processing inlet side, which becomes the driving force for dehumidification. So to speak, dehumidification is carried out by "relative humidity swing". Therefore, even if the regeneration inlet temperature is low, dehumidification can be achieved by creating a relative humidity difference. That is, in the present invention, a reverse phenomenon of processing inlet temperature ≥ regeneration inlet temperature, which cannot be considered in normal temperature swing, occurs, and it is an idea of dehumidification that those skilled in the art cannot easily conceive. Although it is also possible to increase the regeneration inlet temperature to dehumidify as in normal temperature swing, it is not preferable because energy consumption increases. Also, in order to prevent freezing and condensation of the total heat exchanger, the air (regeneration inlet temperature) exiting the heat exchanger 10 is preferably at a temperature at which the regeneration outlet side does not freeze, such as 5°C or higher.

[0047] Normally, the processing outlet temperature rises due to the heat of adsorption that adsorbs moisture on the processing side. However, in the present invention, since the temperature on the regeneration side is low, the rotor remains cold as it rotates from the regeneration zone to the processing zone, and due to the heat storage effect of cold heat, the temperature rise due to the heat of adsorption is suppressed in the processing zone. Therefore, the processing outlet temperature does not rise much, and even if the outside air temperature is low, the temperature inside the house is not lowered by the total heat exchanger. The heat source of the heat exchanger 10 is not particularly limited, but for example, a hot water coil can be used. Since the regeneration inlet temperature is low, the heat exchanger 10 does not require high heating, and it is sufficient to use groundwater or circulating water as the regeneration heat, which is extremely energy-saving. In addition, geothermal heat, ground heat, and solar heat can also be used.

[0048] Note that although the dehumidification mode in winter is particularly effective in cold regions, it is not limited thereto, and it can also be applied to regions with low outside air temperature, such as regions in temperate zones like the Netherlands where the average outside air temperature in winter is, for example, 5°C or lower, and it can exhibit effects.

Example

[0049] (Total heat exchange unit) FIG. 5 shows an example of a side view of a total heat exchange unit including a total heat exchanger used in a closed house according to Example 3 of the present invention. The closed house mainly consists of a cultivation room, a corridor, and a total heat exchange unit. A corridor is a passageway or gallery attached to a building and is used as an air passage. In the present invention, the cultivation room and the total heat exchange unit are connected via the corridor. The total heat exchange unit consists of a total heat exchange rotor 5, fans 8 and 9, a heat exchanger 10, and louvers 11 (11a, 11b, 11c). The louvers 11a and 11b are provided at the upper and lower parts of the side walls of the total heat exchange unit, respectively. When the closed house is released and opened, the air inside the house is ventilated through the louver 11a and discharged outside the house. The louver 11c is attached to the lower part of the wall (not shown) in front of the total heat exchange unit. Outside air is taken into the regeneration zone 7 of the total heat exchange rotor 5 through the louver 11c, and the air leaving the regeneration zone 7 is exhausted through the louver 11b.

[0050] The flow path switching device 12 shown by the broken line is attached, for example, to the inner wall side of the total heat exchange unit, and is provided so as to be rotatable about the louver 11a, and switches the flow path so as to exhaust the air in the house from the louver 11a, or to send the air in the house to the total heat exchange rotor 5. The blower 8 on the treatment side is provided on the upper part of the total heat exchange rotor 5. When the house is closed as a closed house, the flow path switching device 12 closes the louver 11a, and sends the air in the house that has passed through the blower 8 to the treatment zone 6 of the total heat exchange rotor 5. On the other hand, when the air in the house is not subjected to total heat exchange or dehumidification, and the closed house is released and opened, the flow path switching device 12 closes the flow path leading to the treatment side of the total heat exchange rotor 5 on the upper part of the total heat exchange unit, and exhausts the air in the house that has passed through the blower 8 through the louver 11a. In this way, by providing the flow path switching device 12, it is possible to easily switch between closing and releasing (opening) the house. In addition, the total heat exchange unit is made compact by taking advantage of the height of the house, and the installation area can be reduced.

[0051] Warm air tends to accumulate at the upper part of the house, while cold air tends to accumulate at the lower part of the house. Since the side openings of the house are basically provided below the eaves, hot air accumulates at the upper part of the house, and overheating becomes a problem in summer. In the total heat exchange unit shown in Fig. 5, during spring to autumn, air with a high temperature at the upper part of the house is sucked in from the upper part by the blower 8, and the air with reduced temperature is pushed out and supplied from the lower part, causing air circulation. In winter, air slightly warmer than the air inside the house is supplied from the lower part. Since this warm air naturally moves to the upper part of the house, slight natural convection occurs separately from the forced convection from the total heat exchanger. Also, for the supply of air into the house, vinyl ducts or the like can be used. Furthermore, if the duct is such that its collapse due to its own weight is reduced, that is, if the duct itself can maintain the space of the flow path, the pressure loss during air blowing can be reduced, and air can flow more efficiently. For example, those whose duct shape can be maintained by wires, tent structures, hanging structures, etc. fall under this category.

[0052] The air that has passed through the treatment zone 6 passes through the corridor and is supplied into the house through the ducts provided in the cultivation room. Note that the air flow inside the house is not limited to blowing out from the lower part and discharging from the upper part to the cultivation room as shown in Fig. 5. The configuration of the total heat exchange unit can be reversed (the upper side as the regeneration zone 7 and the lower side as the treatment zone 6), resulting in a reverse flow. Also, a booster fan can be added to the corridor in front of the ducts provided in the cultivation room to change the blowing direction. The cultivation room and the total heat exchange unit are connected via the corridor. By sandwiching the corridor, not only a newly built house but also a closed house connected to an existing house can be realized. In Fig. 5, the corridor is installed outside the cultivation room, but it can also be installed inside the cultivation room. Also, when connecting the cultivation room and the total heat exchange unit, ducts can be used in addition to the corridor, or they can be connected only by ducts without providing a corridor.

[0053] In FIGS. 3 and 5, the blower 8 is arranged on the processing inlet side and the blower 9 is arranged on the regeneration outlet side, but it is not limited to this. For example, by providing the blower 9 on the regeneration inlet side, the heating effect on the regeneration side can be enhanced by the temperature rise caused by the blower. Also, although the total heat exchange rotor is in the vertical direction, it may be installed in the horizontal direction or multiple ones may be installed. The flow of each air is not limited to that shown, and the processing zone 6 of the total heat exchange rotor 5 may be on the lower side and the regeneration zone 7 may be on the upper side. Further, the total heat exchange rotor 5 may be configured to have another zone in addition to the processing zone and the regeneration zone. A bypass path may be provided to bypass the processing zone 6 or the regeneration zone 7. A bypass damper may be provided in the total heat exchanger to perform bypass control so as not to pass through the heat exchanger 10. Furthermore, the total heat exchanger is not limited to the total heat exchange rotor, and two or more stationary cross-flow total heat exchangers may be installed, and the total heat exchange mode and the dehumidification mode may be switched by performing batch processing (indoor air ventilation) and regeneration (outdoor air ventilation) switching and controlling the ventilation time and the like.

[0054] As described above, by performing total heat exchange or dehumidification by the total heat exchanger, an air flow is generated in the closed house. As described above, simply closing the house makes the air flow weak, and even if the leaf stomata are open, photosynthesis is suppressed. However, the total heat exchanger can create an air flow in the house and promote the photosynthesis of the leaves. Also, due to the presence of the air flow, it is possible to make the temperature, humidity, and carbon dioxide concentration in the house uniform.

[0055] In the closed house of the present invention, when the house is closed, the temperature and humidity are adjusted by the total heat exchanger and carbon dioxide is supplied using the carbon dioxide supply device, it is possible to maintain the carbon dioxide concentration at a high concentration of 800 to 1000 ppm.

Industrial Applicability

[0056] The closed house of the present invention can stably supply air with suitable temperature and humidity for plant growth throughout the year, so it is particularly effective when applied to cold regions where the outside air temperature often drops below freezing in winter. In addition, it is applicable not only to houses for plant growth but also to the internal environment control of closed spaces such as buildings that need to keep the indoor environment constant and reactors that house chemical reaction systems that dislike moisture. Furthermore, as long as it is an indoor space isolated from the outside air, by using the carbon dioxide supply device of the present invention as a supply device for other gases such as oxygen and nitrogen, it can also be applied to other uses such as closed spaces other than houses.

Explanation of symbols

[0057] 1 House 2 Carbon dioxide supply device 3 Total heat exchanger 4 Adsorption rotor 5 Total heat exchange rotor 6 Treatment zone (indoor air ventilation zone) 7 Regeneration zone (outside air ventilation zone) 8, 9 Blower 10 Heat exchanger 11 Gallery 12 Flow path switching device

Claims

1. In a house equipped with a total heat exchanger, the total heat exchanger has two operating modes: a total heat exchange mode and a dehumidification mode. In the total heat exchange mode, the air inside the house is subjected to total heat exchange with the outside air to lower the temperature and humidity, and then returned to the inside of the house again. In the dehumidification mode, the air inside the house is dehumidified to lower the humidity, and then returned to the inside of the house again. A closed house characterized in that the environment inside the house can be adjusted to an optimal temperature and humidity throughout the year by switching the operating mode.

2. The closed house according to claim 1, wherein the total heat exchanger uses a total heat exchange rotor.

3. The closed house according to claim 2, wherein the total heat exchange rotor rotates at a high speed in the total heat exchange mode and at a low speed in the dehumidification mode, and the operating mode is switched by adjusting the rotation speed.

4. The closed house according to claim 2, wherein the total heat exchange rotor has at least a processing zone and a regeneration zone, the air inside the house passes through the processing zone and is supplied back into the house again, and the outside air passes through the regeneration zone and is exhausted.

5. The closed house according to claim 4, wherein a heat exchanger is provided in front of the regeneration zone, and the outside air is heated by the heat exchanger and sent to the regeneration zone.

6. The closed house according to claim 4 or claim 5, wherein in the total heat exchange rotor, the regeneration inlet temperature is equal to or lower than the processing inlet temperature.

7. A closed house characterized in that it has a carbon dioxide supply device in the closed house according to claim 1.

8. The carbon dioxide supply device is provided with an adsorption rotor. The adsorption rotor has at least an adsorption zone and a desorption zone. The outside air is passed through the adsorption zone to adsorb and exhaust carbon dioxide, and the air inside the house is heated and passed through the desorption zone to desorb carbon dioxide and supply high-concentration carbon dioxide into the house. The closed house according to claim 7 is characterized by this.

9. The closed house according to claim 1 is composed of a cultivation room, a corridor, and a total heat exchange unit. The total heat exchange unit includes the total heat exchanger, and the total heat exchange unit is connected via the cultivation room and the corridor. A closed house characterized by this.

10. The total heat exchange unit is provided with a flow path switching device, and the flow path switching device switches the flow path so as to exhaust the air in the house or send the air in the house to the total heat exchanger. The closed house according to claim 9, characterized in that.

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