JP2017203592A - Humidity controlling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably avoid liquid compression in starting humidity controlling operation subsequent to ventilation operation.SOLUTION: In a humidity controlling device, a control part controls air having a lower detection temperature of outdoor air and indoor air to pass through adsorption heat exchangers (51, 52) to serve as a condenser in the next humidity controlling operation while opening an expansion valve (55) when a difference between outdoor air temperature and indoor air temperature exceeds a first value, and closes the expansion valve (55) when the difference between the outdoor air temperature and the indoor air temperature becomes lower than a second value that is equal to or lower than the first value, in ventilation operation.SELECTED DRAWING: Figure 2

Description

    The present invention relates to a humidity control apparatus.

    2. Description of the Related Art Conventionally, a humidity control device that adjusts humidity in an indoor space is known. As this humidity control apparatus, there is a humidity control apparatus provided with an adsorption heat exchanger carrying an adsorbent that adsorbs moisture. Patent Document 1 discloses this type of humidity control apparatus.

    This humidity control apparatus includes a refrigerant circuit to which a compressor, first and second adsorption heat exchangers, an expansion valve, and a four-way switching valve are connected, and two adsorption heat exchangers are accommodated in a casing. In the humidity control apparatus, the first operation and the second operation are alternately repeated by switching the states of the four-way switching valve and the plurality of dampers.

    For example, in the first operation of the dehumidifying operation, a refrigeration cycle is performed in which the first adsorption heat exchanger serves as a condenser and the second adsorption heat exchanger serves as an evaporator. At the same time, outdoor air passes through the second adsorption heat exchanger, and indoor air passes through the first adsorption heat exchanger. In the second adsorption heat exchanger, moisture in the air is adsorbed by the adsorbent, and the air is dehumidified. The dehumidified air is supplied into the room. In the first adsorption heat exchanger, moisture is released from the adsorbent to the air. The air from which moisture has been released is discharged outside the room.

    For example, in the second operation of the dehumidifying operation, a refrigeration cycle in which the second adsorption heat exchanger serves as a condenser and the first adsorption heat exchanger serves as an evaporator is performed. At the same time, outdoor air passes through the first adsorption heat exchanger, and indoor air passes through the second adsorption heat exchanger. In the first adsorption heat exchanger, moisture in the air is adsorbed by the adsorbent, and the air is dehumidified. The dehumidified air is supplied into the room. In the second adsorption heat exchanger, moisture is released from the adsorbent to the air. The air from which moisture has been released is discharged outside the room.

    Further, the humidity control apparatus of the same document performs a ventilation operation (simple ventilation operation) in which the indoor space is ventilated while the compressor is stopped. That is, in the ventilation operation, the two adsorptive heat exchangers do not substantially function and air conditioning is not performed. Specifically, in the ventilation operation, outdoor air passes through one of the adsorption heat exchangers as it is and then is supplied indoors. At the same time, the room air passes through the other adsorption heat exchanger as it is and is then discharged to the outside.

JP 2013-36731 A

    In the ventilation operation of the humidity control apparatus disclosed in Patent Document 1, since air passes through the adsorption heat exchanger, the cooled refrigerant accumulates as liquid refrigerant inside the adsorption heat exchanger. In this case, in the next humidity control operation, liquid refrigerant may accumulate in the adsorption heat exchanger serving as the evaporator. Therefore, when the humidity control operation is executed in this state and the compressor is operated, the liquid refrigerant in the adsorption heat exchanger on the evaporator side is sucked into the compressor and liquid compression is performed.

    Therefore, in the humidity control apparatus of Patent Document 1, in the ventilation operation, the air having the lower temperature out of the taken outdoor air and indoor air is passed to the adsorption heat exchanger that becomes the condenser in the next humidity control operation. I try to let them. Thereby, while a liquid refrigerant accumulates in the adsorption heat exchanger on the condenser side, it can be avoided that the liquid refrigerant accumulates in the adsorption heat exchanger on the evaporator side. As a result, liquid compression at the start of the subsequent humidity control operation can be avoided.

    However, in the ventilation operation, if a detection error occurs in the temperature sensor (temperature detection unit) that detects the temperature of outdoor air or indoor air, the magnitude relationship between the detected air temperatures and the actual air temperature magnitude of both The relationship may be reversed. When the above operation is performed in such a state, air having a low temperature is actually supplied to the adsorption heat exchanger on the evaporator side, and the accumulation of liquid refrigerant in the adsorption heat exchanger on the evaporator side is promoted. End up. As a result, in the subsequent humidity control operation, there is a risk that a large amount of liquid refrigerant is sucked into the compressor.

    The present invention has been made paying attention to such a point, and an object of the present invention is to reliably prevent liquid compression at the start of the humidity control operation after the ventilation operation.

    The first invention is directed to a humidity control device, and includes a compressor (53), two adsorption heat exchangers (51, 52) each carrying an adsorbent that adsorbs moisture, an expansion valve (55), and four-way switching. A refrigerant circuit (50) to which a valve (54) is connected, a flow path switching mechanism (40) for switching a flow path of air passing through the two adsorption heat exchangers (51, 52), and the compressor (53 ) Is stopped and the outdoor air passes through one adsorption heat exchanger (51, 52) and the indoor air passes through the other adsorption heat exchanger (51, 52), and the compressor (53) Humidity control operation in which one of the outdoor air and the indoor air passes through the adsorption heat exchanger (51, 52) serving as a condenser and the other passes through the adsorption heat exchanger (51, 52) serving as an evaporator. A control unit (80) for controlling the refrigerant circuit (50) and the flow path switching mechanism (40) so as to perform an outdoor air temperature detection for detecting the temperature of the outdoor air as an outdoor air temperature. Part (93) and an inside air temperature detection part (91) for detecting the temperature of the room air as the inside air temperature, and the control part (80) is configured to provide a difference between the outside air temperature and the inside air temperature in the ventilation operation. Becomes larger than the first value, while the expansion valve (55) is opened, the outdoor air and the indoor air having the lower detection temperature are adsorbed by the next humidity control operation. The expansion valve (55) is closed when the difference between the outside air temperature and the inside air temperature becomes smaller than a second value equal to or less than a first value when passing through a heat exchanger (51, 52).

    In the humidity control apparatus of the first invention, the humidity control operation and the ventilation operation are performed. In the humidity control operation, the compressor (53) of the refrigerant circuit (50) is operated, and one adsorption heat exchanger (51, 52) becomes a condenser and the other adsorption heat exchanger (51, 52) becomes an evaporator. A refrigeration cycle is performed. For example, when outdoor air passes through the adsorption heat exchanger (51, 52) serving as an evaporator, moisture in the air is adsorbed by the adsorbent. The air thus dehumidified is supplied indoors. At the same time, when the indoor air passes through the adsorption heat exchanger (51, 52) serving as a condenser, the moisture of the adsorbent is released into the air and the adsorbent is regenerated. For example, when outdoor air passes through the adsorption heat exchanger (51, 52) serving as a condenser, moisture of the adsorbent is released into the air. The air thus humidified is supplied into the room. At the same time, when the indoor air passes through the adsorption heat exchanger (51, 52) serving as an evaporator, moisture in the air is adsorbed by the adsorbent.

    In the ventilation operation, the compressor (53) of the refrigerant circuit (50) stops, and at the same time, the outdoor air passes through one adsorption heat exchanger (51, 52) and the indoor air passes through the other adsorption heat exchanger (51, 52). Go through 52). In this ventilation operation, the refrigerant circuit (50) and the flow path switching mechanism (40) are controlled based on the outside air temperature detected by the outside air temperature detecting unit (93) and the inside air temperature detected by the inside air temperature detecting unit (91). Is done.

    Specifically, it is assumed that the difference between the outside air temperature and the inside air temperature is larger than the first value. In this case, the difference between the detection values of the inside air temperature detection unit (91) and the outside air temperature detection unit (93) is sufficiently large so that even if there is a detection error, it is not affected by the determination of the magnitude relationship between the outside air temperature and the inside air temperature. Perceived to be larger. Therefore, in the ventilation operation, in such a case, the air having the lower detected temperature of the outdoor air and the indoor air is transferred to the adsorption heat exchanger (51, 52) that becomes the condenser in the next humidity control operation. Let it pass. At the same time, the expansion valve (55) of the refrigerant circuit (50) is opened. In this way, the refrigerant inside the adsorption heat exchanger (51, 52) on the evaporator side moves to the adsorption heat exchanger (51, 52) on the condenser side that is cooled by air. At this time, since there is a sufficient temperature difference between the outside air temperature and the inside air temperature, it is possible to prevent the higher temperature air from being supplied to the adsorption heat exchanger (51, 52) on the evaporator side due to detection errors. it can. As a result, in the next humidity control operation, the liquid refrigerant accumulated in the adsorption heat exchanger (51, 52) on the evaporator side can be prevented from being sucked into the compressor (53).

    Further, it is assumed that the difference between the outside air temperature and the inside air temperature is smaller than a second value equal to or less than the first value. In this case, due to the detection error of the outside air temperature detection unit (93) and the inside air temperature detection unit (91), the magnitude relationship between the detected outside air temperature and the inside air temperature is reversed from the actual magnitude relationship between the outdoor air and the room air. there's a possibility that. Therefore, in the ventilation operation, in such a case, the expansion valve (55) of the refrigerant circuit (50) is fully closed. In this way, the refrigerant is prevented from moving between the two adsorption heat exchangers (51, 52) by the fully closed expansion valve (55). Therefore, the refrigerant is not biased to one of the adsorption heat exchangers (51, 52) regardless of the temperature of the air passing through each of the adsorption heat exchangers (51, 52). As a result, it is ensured that the liquid refrigerant accumulates in the adsorption heat exchanger (51, 52) on the evaporator side due to the detection error of the outside air temperature detector (93) and the inside air temperature detector (91). Can be avoided.

    In a second aspect based on the first aspect, the control unit (80) is configured such that, in the ventilation operation, when the expansion valve (55) is in a closed state, at least one of the outside air temperature and the inside air temperature is When the temperature is higher than a predetermined temperature, the expansion valve (55) is opened.

    In the ventilation operation of the second invention, when at least one of the outside air temperature and the inside air temperature becomes higher than the predetermined temperature when the expansion valve (55) is in the closed state, the expansion valve (55) is opened. That is, when the expansion valve (55) is closed under conditions where the outside air temperature and the inside air temperature are extremely high, the adsorption of the adsorption air due to the passage of hot air through the adsorption heat exchanger (51, 52) The refrigerant in the heat exchanger (51, 52) is heated. Then, the volume of the refrigerant increases and the pressure inside the adsorption heat exchanger (51, 52) increases rapidly, which may cause damage to the piping. Therefore, when the outside air temperature or the inside air temperature becomes higher than a predetermined temperature, the expansion valve (55) is opened. Thereby, since the internal pressures of the two adsorption heat exchangers (51, 52) are made uniform, it is possible to quickly avoid the internal pressure of the adsorption heat exchangers (51, 52) from becoming extremely high.

    According to a third invention, in the first or second invention, the first value is larger than the second value.

    In the third aspect of the invention, the first value that is the reference for opening the expansion valve (55) is greater than the second value that is the reference for closing the expansion valve (55). In this way, the difference between the outside air temperature and the inside air temperature is less likely to be greater than the first value, and therefore the expansion valve (55) is difficult to open. Therefore, it is possible to reliably prevent the refrigerant from accumulating in the adsorption heat exchanger (51, 52) on the evaporator side by mistake.

    According to the present invention, when the difference between the outside air temperature and the inside air temperature is small, the expansion valve (55) is closed, which is caused by the detection error of the outside air temperature detecting unit (93) and the inside air temperature detecting unit (91). Thus, the refrigerant can be reliably prevented from moving to the adsorption heat exchanger (51, 52) on the evaporator side. Therefore, it is possible to reliably prevent the liquid refrigerant in the adsorption heat exchanger (51, 52) serving as an evaporator from being directly sucked into the compressor (53) in the subsequent humidity control operation.

FIG. 1 is a plan view, a right side view, and a left side view showing a schematic structure of a humidity control apparatus according to an embodiment. FIG. 2 is a piping system diagram showing the configuration of the refrigerant circuit. FIG. 3 is a diagram comparing refrigerant circuits according to the state of the expansion valve and the air flow path, and shows the flow of refrigerant and the flow of air. FIG. 4 is a block diagram illustrating a configuration of a controller of the humidity control apparatus according to the embodiment. FIG. 5 is a schematic plan view, right side view, and left side view of the humidity control apparatus showing the air flow during the first operation of the dehumidifying operation. FIG. 6 is a schematic plan view, a right side view, and a left side view of the humidity control apparatus showing the air flow during the second operation of the dehumidifying operation. FIG. 7 is a schematic plan view, right side view, and left side view of the humidity control apparatus showing the air flow during the first operation of the humidification operation. FIG. 8 is a schematic plan view, right side view, and left side view of the humidity control apparatus showing the flow of air during the second operation of the humidification operation. FIG. 9 is a schematic plan view, right side view, and left side view of the humidity control apparatus showing a state in which the air flow path is set to the first path during the simple ventilation operation. FIG. 10 is a schematic plan view, right side view, and left side view of the humidity control apparatus showing a state in which the air flow path is set to the second path during the simple ventilation operation. FIG. 11 is a state transition diagram of simple ventilation operation. FIG. 12 is a diagram showing determination conditions at the start of simple ventilation operation. FIG. 13 is a diagram illustrating determination conditions for simple ventilation operation.

    Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following embodiments are essentially preferable examples, and are not intended to limit the scope of the present invention, its application, or its use.

    The humidity control apparatus (10) of the present embodiment is for adjusting the humidity of the indoor space and ventilating the indoor space. The humidity of the sucked outdoor air (OA) is adjusted and supplied to the indoor space. Exhaust air (RA) into the outdoor space.

<Overall configuration of humidity control device>
The humidity control apparatus (10) will be described with reference to FIG. Note that “upper”, “lower”, “left”, “right”, “front”, “rear”, “front”, and “rear” used in the description here are the humidity control device (10) from the front side. It means the direction when viewed.

    The humidity control device (10) includes a casing (11). A refrigerant circuit (50) is accommodated in the casing (11). The refrigerant circuit (50) includes a first adsorption heat exchanger (51), a second adsorption heat exchanger (52), a compressor (53), a four-way switching valve (54), and an electric expansion valve (55). It is connected. Details of the refrigerant circuit (50) will be described later.

    The casing (11) is formed in a rectangular parallelepiped shape that is slightly flat and relatively low in height. The casing (11) is formed with an outside air suction port (24), an inside air suction port (23), an air supply port (22), and an exhaust port (21). The outdoor air suction port (24) and the exhaust port (21) communicate with the outdoor space via ducts. The room air intake port (23) and the air supply port (22) communicate with the indoor space via ducts.

    The outside air suction port (24) and the inside air suction port (23) are provided in the back panel portion (13) of the casing (11). The outside air inlet (24) is provided in the lower part of the back panel (13). The inside air suction port (23) is provided in the upper part of the back panel (13). The air supply port (22) is provided in the first side panel (14) of the casing (11). In the first side panel (14), the air supply port (22) is disposed near the end of the casing (11) on the front panel (12) side. The exhaust port (21) is provided in the second side panel (15) of the casing (11). In the second side panel portion (15), the exhaust port (21) is disposed near the end portion on the front panel portion (12) side.

    An upstream partition plate (71), a downstream partition plate (72), and a central partition plate (73) are provided in the internal space of the casing (11). These partition plates (71 to 73) are all installed upright on the bottom plate of the casing (11), and the internal space of the casing (11) is partitioned from the bottom plate of the casing (11) to the top plate. doing.

    The upstream divider plate (71) and the downstream divider plate (72) are parallel to the front panel portion (12) and the rear panel portion (13), and are spaced at a predetermined interval in the longitudinal direction of the casing (11). Is arranged. The upstream divider plate (71) is disposed closer to the rear panel portion (13). The downstream partition plate (72) is disposed closer to the front panel portion (12). The arrangement of the central partition plate (73) will be described later.

    In the casing (11), the space between the upstream divider plate (71) and the back panel (13) is divided into two upper and lower spaces, and the upper space forms the inside air passage (32). The lower space constitutes the outside air passage (34). The inside air passage (32) communicates with the inside air inlet (23), and the outside air passage (34) communicates with the outside air inlet (24).

    An inside air side filter (27), an inside air temperature sensor (91), and an inside air humidity sensor (92) are installed in the inside air passage (32). The room air temperature sensor (91) measures the temperature of the room air flowing through the room air side passage (32). The room air humidity sensor (92) measures the relative humidity of the room air flowing through the room air side passage (32). On the other hand, an outside air filter (28), an outside air temperature sensor (93), and an outside air humidity sensor (94) are installed in the outside air passage (34). The outside air temperature sensor (93) measures the temperature of the outdoor air flowing through the outside air passage (34). The outside air humidity sensor (94) measures the relative humidity of the outdoor air flowing through the outside air passage (34). 5 to 8, the inside air temperature sensor (91), the inside air humidity sensor (92), the outside air temperature sensor (93), and the outside air humidity sensor (94) are not shown. The room air temperature sensor (91) constitutes a room air detector that detects the temperature of the room air (the room air temperature Tr). The outside air temperature sensor (93) constitutes an outside air temperature detector that detects the temperature of the outdoor air (outside air temperature To).

    The space between the upstream divider plate (71) and the downstream divider plate (72) in the casing (11) is divided into left and right by the central divider plate (73), and is located on the right side of the central divider plate (73). The space constitutes the first heat exchanger chamber (37), and the space on the left side of the central partition plate (73) constitutes the second heat exchanger chamber (38). A first adsorption heat exchanger (51) is accommodated in the first heat exchanger chamber (37). The second adsorption heat exchanger (52) is accommodated in the second heat exchanger chamber (38). Moreover, although not shown in figure, the electric expansion valve (55) of a refrigerant circuit (50) is accommodated in the 1st heat exchanger chamber (37).

    Each adsorption heat exchanger (51, 52) has an adsorbent supported on the surface of a so-called cross fin type fin-and-tube heat exchanger. As this adsorbent, materials capable of adsorbing moisture in the air, such as zeolite, silica gel, activated carbon, and organic polymer materials having a hydrophilic functional group, are used. The “adsorbent” in the present specification includes a material that performs both adsorption and absorption of water vapor (so-called sorbent).

    Each adsorption heat exchanger (51, 52) is formed in the shape of a rectangular thick plate or a flat rectangular parallelepiped as a whole. Each adsorption heat exchanger (51, 52) has a front face and a rear face parallel to the upstream partition plate (71) and the downstream partition plate (72), and the heat exchanger chamber (37, 38). It is installed in a standing state.

    In the internal space of the casing (11), the space along the front surface of the downstream partition plate (72) is partitioned vertically, and the upper portion of the vertically partitioned space is the air supply side passage ( 31), and the lower part constitutes the exhaust side passage (33).

    The upstream partition plate (71) is provided with four open / close dampers (41 to 44). Each damper (41-44) is formed in the shape of a substantially horizontally long rectangle. Specifically, in a part (upper part) facing the room air passage (32) in the upstream partition (71), the first room air damper (41) is attached to the right side of the central partition (73). The second inside air damper (42) is attached to the left side of the central partition plate (73). A portion of the upstream divider plate (71) facing the outside air passage (34) (lower portion) is provided with a first outside air damper (43) on the right side of the center divider plate (73). A second outside air damper (44) is attached to the left side of the plate (73).

    The downstream partition plate (72) is provided with four open / close dampers (45 to 48). Each damper (45-48) is formed in the shape of a substantially horizontally long rectangle. Specifically, in the part (upper part) facing the supply side passageway (31) in the downstream partition plate (72), the first supply side damper (45) is located on the right side of the central partition plate (73). The second air supply side damper (46) is attached to the left side of the central partition plate (73). The first exhaust side damper (47) is attached to the right side of the central partition plate (73) at the portion (lower part) facing the exhaust side passage (33) in the downstream side partition plate (72). A second exhaust side damper (48) is attached to the left side of the plate (73).

    The eight dampers (41 to 48) described above constitute a flow path switching mechanism (40) that switches the air flow path. The flow path switching mechanism (40) switches the air flow path between the first path and the second path by opening and closing the eight dampers (41 to 48), respectively.

    When forming the first path, the second inside air side damper (42), the first outside air side damper (43), the first air supply side damper (45), and the second exhaust side damper (48) are opened, The first inside air side damper (41), the second outside air side damper (44), the second air supply side damper (46), and the first exhaust side damper (47) are closed. In this state, outdoor air passes through the first adsorption heat exchanger (51) and is then supplied to the room, and at the same time, indoor air passes through the second adsorption heat exchanger (52) and is then discharged to the outside. The

    When forming the second path, the first inside air damper (41), the second outside air side damper (44), the second air supply side damper (46), and the first exhaust side damper (47) are opened, The second inside air side damper (42), the first outside air side damper (43), the first air supply side damper (45), and the second exhaust side damper (48) are closed. In this state, outdoor air passes through the second adsorption heat exchanger (52) and is then supplied to the room. At the same time, indoor air passes through the first adsorption heat exchanger (51) and is then discharged to the outside. The

    In the casing (11), the space between the air supply side passage (31) and the exhaust side passage (33) and the front panel portion (12) is divided into left and right by the partition plate (77). The space on the right side of (77) constitutes the air supply fan chamber (36), and the space on the left side of the partition plate (77) constitutes the exhaust fan chamber (35).

    The air supply fan (26) is accommodated in the air supply fan chamber (36). The exhaust fan chamber (35) accommodates an exhaust fan (25). The supply fan (26) and the exhaust fan (25) are both centrifugal multiblade fans (so-called sirocco fans). The air supply fan (26) blows out the air sucked from the downstream side partition plate (72) side to the air supply port (22). The exhaust fan (25) blows out the air sucked from the downstream partition plate (72) side to the exhaust port (21).

    The supply fan chamber (36) accommodates the compressor (53) and the four-way switching valve (54) of the refrigerant circuit (50). The compressor (53) and the four-way selector valve (54) are disposed between the air supply fan (26) and the partition plate (77) in the air supply fan chamber (36).

<Configuration of refrigerant circuit>
As shown in FIG. 2, the refrigerant circuit (50) includes a first adsorption heat exchanger (51), a second adsorption heat exchanger (52), a compressor (53), a four-way switching valve (54), and an electric expansion. It is a closed circuit provided with a valve (55). The refrigerant circuit (50) performs a vapor compression refrigeration cycle by circulating the filled refrigerant. Although not shown, the refrigerant circuit (50) is provided with a plurality of temperature sensors and pressure sensors.

    In the refrigerant circuit (50), the compressor (53) has its discharge pipe connected to the first port of the four-way switching valve (54) and its suction pipe connected to the second port of the four-way switching valve (54). ing. In the refrigerant circuit (50), the first adsorption heat exchanger (51) and the electric expansion valve (55) (expansion valve) are sequentially arranged from the third port to the fourth port of the four-way switching valve (54). ) And a second adsorption heat exchanger (52).

    The four-way switching valve (54) has a first state (state indicated by a solid line in FIG. 2) in which the first port and the third port communicate with each other and the second port and the fourth port communicate with each other, It is possible to switch to a second state (state indicated by a broken line in FIG. 2) in which the port communicates with the fourth port and the second port communicates with the third port.

    The compressor (53) is a hermetic compressor in which a compression mechanism and an electric motor that drives the compression mechanism are housed in one casing. Alternating current is supplied to the electric motor of the compressor (53) via an inverter. When the output frequency of the inverter (that is, the operating frequency of the compressor (53)) is changed, the rotational speed of the electric motor and the compression mechanism driven thereby changes, and the operating capacity of the compressor (53) changes. Increasing the rotational speed of the compression mechanism increases the operating capacity of the compressor (53), and decreasing the rotational speed of the compression mechanism decreases the operating capacity of the compressor (53).

    The refrigerant circuit (50) is provided with a discharge pressure sensor (61), a suction pressure sensor (62), a discharge temperature sensor (63), and a suction temperature sensor (64). The discharge pressure sensor (61) detects the pressure of the discharge refrigerant (high pressure refrigerant) discharged from the compressor (53). The suction pressure sensor (62) detects the pressure of the suction refrigerant (low pressure refrigerant) sucked into the compressor (53). The discharge temperature sensor (63) detects the temperature of the discharge refrigerant discharged from the compressor (53). The suction temperature sensor (64) detects the temperature of the suction refrigerant sucked into the compressor (53).

<Configuration of controller>
The humidity control device (10) is provided with a controller (80) as a control unit. The controller (80) receives the measured values of the inside air humidity sensor (92), the inside air temperature sensor (91), the outside air humidity sensor (94), and the outside air temperature sensor (93). The controller (80) receives the measured values of the pressure sensors (61, 62) and the temperature sensors (63, 64) provided in the refrigerant circuit (50). The controller (80) controls the flow path switching mechanism (40) and the refrigerant circuit (50) of the humidity control apparatus (10) based on these input measurement values and signals. Specifically, the controller (80) controls each damper (41 to 48), each fan (25, 26), the compressor (53), the electric expansion valve (55), and the four-way switching valve (54). .

    As shown in FIG. 4, the controller (80) includes a compressor control unit (81), a four-way switching valve control unit (82), an expansion valve control unit (83), a damper control unit (84), and a timer unit (85 )have. The compressor control unit (81) performs switching between starting and stopping of the compressor (53) and adjusting the rotational speed of the compressor (53). The four-way switching valve control unit (82) performs control to switch the four-way switching valve (54) between the first state and the second state. The expansion valve control unit (83) performs control to adjust the opening degree of the electric expansion valve (55). The damper control unit (84) performs control for switching opening and closing of the flow path switching mechanism (40) (each damper (41 to 48)). The timer unit (85) counts time for executing antifreezing control, which will be described later in detail.

-Driving action-
First, the basic operation of the humidity control apparatus (10) will be described. The humidity control device (10) selectively performs a dehumidifying operation, a humidifying operation, and a simple ventilation operation. The dehumidifying operation and the humidifying operation are humidity adjusting operations for the purpose of adjusting the absolute humidity of the outdoor air supplied to the indoor space. That is, the dehumidifying operation and the humidifying operation are operations for mainly processing a latent heat load (dehumidifying load or humidifying load) in the indoor space. The simple ventilation operation is an operation for performing only ventilation of the indoor space.

    In each of the dehumidifying operation, the humidifying operation, and the simple ventilation operation, the air supply fan (26) and the exhaust fan (25) operate. The humidity control apparatus (10) supplies the sucked outdoor air (OA) to the indoor space as supply air (SA), and discharges the sucked indoor air (RA) to the outdoor space as exhaust air (EA).

<Dehumidifying operation>
In the humidity control apparatus (10) during the dehumidifying operation, outdoor air is sucked into the casing (11) from the outside air inlet (24) as first air, and indoor air is drawn from the inside air inlet (23) into the casing (11). Into the second air. In the refrigerant circuit (50), the compressor (53) operates, and the opening degree of the electric expansion valve (55) is adjusted. The humidity control apparatus (10) during the dehumidifying operation repeats the first operation and the second operation alternately for 3 minutes.

    As shown in FIGS. 3B and 5, in the first operation of the dehumidifying operation, the switching mechanism (40) sets the air flow path to the second path. During the first operation, the four-way switching valve (54) is set to the first state. In the refrigerant circuit (50), a refrigeration cycle is performed, the first adsorption heat exchanger (51) functions as a condenser (that is, a radiator), and the second adsorption heat exchanger (52) functions as an evaporator. To do.

    The first air flowing into the outside air passage (34) flows into the second heat exchanger chamber (38) through the second outside air damper (44), and then passes through the second adsorption heat exchanger (52). pass. In the second adsorption heat exchanger (52), moisture in the first air is adsorbed by the adsorbent, and the heat of adsorption generated at that time is absorbed by the refrigerant. Further, in the second adsorption heat exchanger (52), the temperature of the first air is somewhat lowered. The first air dehumidified in the second adsorption heat exchanger (52) flows through the second air supply damper (46) into the air supply passage (31) and passes through the air supply fan chamber (36). Later, the air is supplied to the indoor space through the air supply port (22).

    On the other hand, the 2nd air which flowed into the inside air side passage (32) flows into the 1st heat exchanger room (37) through the 1st inside air side damper (41), and after that, the 1st adsorption heat exchanger (51 ). In the first adsorption heat exchanger (51), moisture is desorbed from the adsorbent heated by the refrigerant, and the desorbed moisture is given to the second air. The second air given moisture in the first adsorption heat exchanger (51) flows into the exhaust side passage (33) through the first exhaust side damper (47) and passes through the exhaust fan chamber (35). It is discharged to the outdoor space through the exhaust port (21).

    As shown in FIGS. 3C and 6, in the second operation of the dehumidifying operation, the switching mechanism (40) sets the air flow path to the first path. During this second operation, the four-way switching valve (54) is set to the second state. In the refrigerant circuit (50), a refrigeration cycle is performed, the second adsorption heat exchanger (52) functions as a condenser (ie, a radiator), and the first adsorption heat exchanger (51) functions as an evaporator. To do.

    The first air that has flowed into the outside air passage (34) flows into the first heat exchanger chamber (37) through the first outside air damper (43), and then passes through the first adsorption heat exchanger (51). pass. In the first adsorption heat exchanger (51), moisture in the first air is adsorbed by the adsorbent, and the adsorption heat generated at that time is absorbed by the refrigerant. Moreover, in the 1st adsorption heat exchanger (51), the temperature of 1st air falls somewhat. The first air dehumidified in the first adsorption heat exchanger (51) flows into the supply air passage (31) through the first supply air damper (45) and passes through the supply air fan chamber (36). Later, the air is supplied to the indoor space through the air supply port (22).

    On the other hand, the 2nd air which flowed into the inside air side passage (32) flows into the 2nd heat exchanger room (38) through the 2nd inside air side damper (42), and after that, the 2nd adsorption heat exchanger (52 ). In the second adsorption heat exchanger (52), moisture is desorbed from the adsorbent heated by the refrigerant, and the desorbed moisture is given to the second air. The second air given moisture in the second adsorption heat exchanger (52) flows into the exhaust side passage (33) through the second exhaust side damper (48) and passes through the exhaust fan chamber (35). It is discharged to the outdoor space through the exhaust port (21).

<Humidification operation>
In the humidity control device (10) during the humidifying operation, outdoor air is sucked into the casing (11) from the outside air inlet (24) as second air, and indoor air is drawn from the inside air inlet (23) into the casing (11). Into the first air. In the refrigerant circuit (50), the compressor (53) operates to adjust the opening of the electric expansion valve (55). The humidity control apparatus (10) during the humidifying operation repeatedly performs a first operation and a second operation, which will be described later, alternately every 3 minutes and 30 seconds.

    As shown in FIGS. 3A and 7, in the first operation of the humidifying operation, the switching mechanism (40) sets the air flow path to the first path. In this first operation, the four-way switching valve (54) is set to the first state. In the refrigerant circuit (50), a refrigeration cycle is performed, the first adsorption heat exchanger (51) functions as a condenser (that is, a radiator), and the second adsorption heat exchanger (52) functions as an evaporator. To do.

    The 1st air which flowed into the inside air side passage (32) flows into the 2nd heat exchanger room (38) through the 2nd inside air side damper (42), and the 2nd adsorption heat exchanger (52) is passed after that. pass. In the second adsorption heat exchanger (52), moisture in the first air is adsorbed by the adsorbent, and the heat of adsorption generated at that time is absorbed by the refrigerant. The first air deprived of moisture in the second adsorption heat exchanger (52) flows into the exhaust side passage (33) through the second exhaust side damper (48) and passes through the exhaust fan chamber (35). It is discharged to the outdoor space through the exhaust port (21).

    On the other hand, the second air that has flowed into the outside air passage (34) flows into the first heat exchanger chamber (37) through the first outside air damper (43), and then the first adsorption heat exchanger (51). ). In the first adsorption heat exchanger (51), moisture is desorbed from the adsorbent heated by the refrigerant, and the desorbed moisture is given to the second air. In the first adsorption heat exchanger (51), the temperature of the second air rises somewhat. The second air humidified in the first adsorption heat exchanger (51) flows into the supply air passage (31) through the first supply air damper (45) and passes through the supply air fan chamber (36). Later, the air is supplied to the indoor space through the air supply port (22).

    As shown in FIG. 3D and FIG. 8, in the second operation of the humidifying operation, the switching mechanism (40) sets the air flow path to the second path. In this second operation, the four-way selector valve (54) is set to the second state. In the refrigerant circuit (50), a refrigeration cycle is performed, the second adsorption heat exchanger (52) functions as a condenser (ie, a radiator), and the first adsorption heat exchanger (51) functions as an evaporator. To do.

    The 1st air which flowed into the inside air side passage (32) flows into the 1st heat exchanger room (37) through the 1st inside air side damper (41), and the 1st adsorption heat exchanger (51) is passed after that. pass. In the first adsorption heat exchanger (51), moisture in the first air is adsorbed by the adsorbent, and the adsorption heat generated at that time is absorbed by the refrigerant. The first air deprived of moisture in the first adsorption heat exchanger (51) flows into the exhaust side passage (33) through the first exhaust side damper (47) and passes through the exhaust fan chamber (35). It is discharged to the outdoor space through the exhaust port (21).

    On the other hand, the second air flowing into the outside air passage (34) flows into the second heat exchanger chamber (38) through the second outside air damper (44), and then the second adsorption heat exchanger (52). ). In the second adsorption heat exchanger (52), moisture is desorbed from the adsorbent heated by the refrigerant, and the desorbed moisture is given to the second air. In the second adsorption heat exchanger (52), the temperature of the second air rises somewhat. The second air humidified in the second adsorption heat exchanger (52) flows into the supply air passage (31) through the second supply air damper (46) and passes through the supply air fan chamber (36). Later, the air is supplied to the indoor space through the air supply port (22).

<Simple ventilation operation>
Simple ventilation operation is operation which ventilates indoor space. In the humidity control apparatus (10) during the simple ventilation operation, the compressor (53) of the refrigerant circuit (50) stops. Further, when the air circulation path is set to the first path, outdoor air and room air flow in the humidity control apparatus (10) as shown in FIG. That is, the outdoor air is supplied to the indoor space after passing through the first adsorption heat exchanger (51), and the indoor air is discharged to the outdoor space after passing through the second adsorption heat exchanger (52).

  On the other hand, when the air circulation path is set to the second path, outdoor air and room air flow in the humidity control apparatus (10) as shown in FIG. That is, outdoor air is supplied to the indoor space after passing through the second adsorption heat exchanger (52), and indoor air is discharged to the outdoor space after passing through the first adsorption heat exchanger (51).

    During the simple ventilation operation, the adsorption heat exchanger (51, 52) does not exchange moisture or heat with the air passing therethrough. Therefore, the outdoor air is supplied to the indoor space as it is without adjusting the temperature and the absolute humidity. Further, the indoor air is discharged to the outdoor space as it is without adjusting the temperature and the absolute humidity.

-Control operation of simple ventilation operation-
In the simple ventilation operation, in order to prevent the refrigerant accumulated in the adsorption heat exchanger (51, 52) from being sucked into the compressor (53) in the subsequent humidity control operation, the four-way switching valve (54), Control operations of the dampers (41 to 48) and the electric expansion valve (55) are performed. This control operation will be described with reference to FIGS.

    As shown in FIG. 11, when the simple ventilation operation is started, first, the controller (80) determines which of condition A, condition B, and condition C is satisfied. These determinations are made based on the inside air temperature Tr detected by the inside air temperature sensor (91) and the outside air temperature To detected by the outside air temperature sensor (93).

    As shown in FIG. 12, when the simple ventilation operation is started, it is first determined whether or not the condition B is satisfied. The inside air temperature Tr is equal to or higher than a value obtained by adding a predetermined temperature T1 (for example, T1 = 3 ° C.) to the outside air temperature To, and the current four-way selector valve (54) is in the first state (state shown by a solid line in FIG. 2). In some cases, condition B is met.

    The fact that the four-way switching valve (54) is in the first state means that at the start of the next humidity control operation, the second adsorption heat exchanger (52) becomes a condenser and the first adsorption heat exchanger (51) It becomes an evaporator. Since the four-way switching valve (54) is driven using the high / low differential pressure of the refrigerant circuit (50), the state of the four-way switching valve (54) in the simple ventilation operation is maintained even at the start of the humidity control operation. Because.

    On the other hand, at the start of the humidity control operation, in order to prevent the liquid refrigerant from being sucked into the compressor (53), the second adsorption heat exchanger (52 that becomes the condenser in the next humidity control operation) ) Needs to store liquid refrigerant. When liquid refrigerant accumulates in the first adsorption heat exchanger (51) that becomes the evaporator, the liquid refrigerant is hardly evaporated and sucked into the compressor (53) when the compressor (53) is started. Because it will end up.

    Therefore, when the four-way switching valve (54) is in the first state and the inside air temperature Tr ≧ the outside air temperature To + 3 ° C. or more, the condition B is satisfied and the state 2 is transited. In state 2, the electric expansion valve (55) is opened at a predetermined opening, and the air flow path is set to the second path. When the second path is set, the outdoor air passes through the second adsorption heat exchanger (52) and the room air passes through the first adsorption heat exchanger (51). That is, in this state, outdoor air having a temperature of 3 ° C. or more passes between the outdoor air and the indoor air through the second adsorption heat exchanger (52) that becomes a condenser in the next humidity control operation. At the same time, indoor air having a temperature of 3 ° C. or higher passes between the outdoor air and the indoor air through the first adsorption heat exchanger (51) that becomes an evaporator in the next humidity control operation. At this time, in the refrigerant circuit (50), the electric expansion valve (55) is in an open state. Accordingly, the refrigerant in the first adsorption heat exchanger (51) and the pipe moves to the second adsorption heat exchanger (52) that becomes a condenser, and in the state of liquid refrigerant, the second adsorption heat exchanger (52). Accumulate in the inside of. Thereby, it can avoid that a liquid refrigerant accumulates in the 1st adsorption heat exchanger (51) used as an evaporator by the following humidity control operation.

    As shown in FIG. 12, a value obtained by adding a predetermined temperature T1 (eg, T1 = 3 ° C.) to the inside air temperature Tr is equal to or lower than the outside air temperature To, and the current four-way switching valve (54) is in the second state (FIG. 2). Also, in the case of the state indicated by the broken line of FIG. Thereby, indoor air whose temperature is lower by 3 ° C. or more out of the outdoor air and the indoor air passes through the first adsorption heat exchanger (51) that becomes a condenser in the next humidity control operation. At the same time, outdoor air having a temperature higher by 3 ° C. or more out of the outdoor air and the indoor air passes through the second adsorption heat exchanger (52) serving as an evaporator in the next humidity control operation. Thereby, a liquid refrigerant can be stored in the 1st adsorption heat exchanger (51) used as a condenser by the following humidity control operation.

    When the condition B is not satisfied, it is determined whether or not the condition C is satisfied. Specifically, when the difference (absolute value) between outdoor air and indoor air is smaller than a predetermined temperature T1 (for example, T1 = 3 ° C.), the inside air temperature Tr is 45 ° C. or less, and the outside air temperature is 45 ° C. or less, C is established, and the state 3 is transited.

    Condition C is satisfied when the difference between the inside air temperature Tr and the outside air temperature To is relatively small and the inside air temperature Tr and the outside air temperature To are not very high. The predetermined temperature T1 is a value in consideration of detection errors of the inside air temperature sensor (91) and the outside air temperature sensor (93). That is, when the difference between the inside air temperature Tr and the outside air temperature To is not so large, the actual temperature of the indoor air and the outdoor air is small or large due to detection errors of the inside air temperature sensor (91) and the outside air temperature sensor (93). There is a possibility that the relationship and the magnitude relationship between the detected inside air temperature Tr and the outside air temperature To may be reversed. Therefore, when the state is changed to the state 2 in such a situation, the liquid refrigerant is accumulated in the adsorption heat exchanger (51, 52) serving as an evaporator, and the liquid compression of the compressor (53) can be promoted. There is sex.

    On the other hand, when the difference between the inside air temperature Tr and the outside air temperature To is relatively small as in the condition C, the state does not transit to the state 2 but transits to the state 3. When transitioning to state 3, the electric expansion valve (55) is fully closed. Therefore, even if the lower temperature air flows into the adsorption heat exchanger (51, 52) serving as the evaporator due to the detection error of the inside air temperature sensor (91) or the outside air temperature sensor (93) The condenser-side adsorption heat exchanger (51, 52) does not pass through the electric expansion valve (55) and move to the evaporator-side adsorption heat exchanger (51, 52). Therefore, it is possible to reliably avoid the liquid refrigerant from being biased to the adsorption heat exchangers (51, 52) on the evaporator side due to detection errors of the inside air temperature sensor (91) and the outside air temperature sensor (93).

    When the condition B and the condition C are not satisfied at the start of the humidity control operation, the condition A is satisfied and the state 1 is transited. In state 1, the electric expansion valve (55) is opened at a predetermined opening, and the air flow path is set to the first path.

    Here, the condition A is that the inside air temperature Tr is not less than a value obtained by adding a predetermined temperature T1 (for example, T1 = 3 ° C.) to the outside air temperature To, and the current four-way switching valve (54) is in the second state. Is established. Therefore, when this condition is satisfied, the transition to the state 1 allows relatively low-temperature outdoor air to pass through the second adsorption heat exchanger (52) serving as a condenser, and the first adsorption heat exchange serving as an evaporator. The relatively hot room air passes through the vessel (51). As a result, the liquid refrigerant can be stored in the second adsorption heat exchanger (52) serving as a condenser.

    Condition A also holds when the value obtained by adding a predetermined temperature T1 (eg, T1 = 3 ° C.) to the inside air temperature Tr is equal to or lower than the outside air temperature To, and the current four-way switching valve (54) is in the first state. To do. Therefore, when this condition is satisfied, the transition to the state 1 causes the relatively low temperature outdoor air to pass through the first adsorption heat exchanger (51) serving as a condenser, and the second adsorption heat exchange serving as an evaporator. A relatively hot room air passes through the vessel (52). As a result, the liquid refrigerant can be stored in the first adsorption heat exchanger (51) serving as a condenser.

    Next, transitions of state 1, state 2, and state 3 will be described in detail with reference to FIGS. As described above, in state 1, the electric expansion valve (55) is in the open state, and the air flow path is the first path. In state 2, the electric expansion valve (55) is in the open state, and the air flow path is the second path. In state 3, the electric expansion valve (55) is fully closed, and the air flow path is the first path or the second path.

    In state 2, when condition D is satisfied, the state transitions to state 1. Condition D is established when the inside air temperature Tr is equal to or greater than a value obtained by adding a predetermined temperature T1 (for example, T1 = 3 ° C.) to the outside air temperature To, and the current four-way switching valve (54) is in the second state. . Therefore, when this condition is satisfied, the transition to the state 1 allows the outdoor air having a relatively low temperature to pass through the second adsorption heat exchanger (52) serving as a condenser.

    Condition D is when the value obtained by adding a predetermined temperature T1 (eg, T1 = 3 ° C.) to the inside air temperature Tr is equal to or lower than the outside air temperature To, and the current four-way selector valve (54) is in the first state. Also holds. Therefore, when this condition is satisfied, the transition to the state 1 allows the outdoor air having a relatively low temperature to pass through the first adsorption heat exchanger (51) serving as a condenser.

    In state 1, when condition E is satisfied, the state transitions to state 2. Condition E is established when the inside air temperature Tr is equal to or greater than a value obtained by adding a predetermined temperature T1 (for example, T1 = 3 ° C.) to the outside air temperature To, and the current four-way switching valve (54) is in the first state. . Therefore, when this condition is satisfied, the transition to the state 2 allows relatively low temperature outdoor air to pass through the first adsorption heat exchanger (51) serving as a condenser.

    Condition E is when the value obtained by adding a predetermined temperature T1 (eg, T1 = 3 ° C.) to the inside air temperature Tr is equal to or lower than the outside air temperature To, and the current four-way selector valve (54) is in the second state. Also holds. Therefore, when this condition is satisfied, the transition to the state 2 allows relatively low temperature outdoor air to pass through the second adsorption heat exchanger (52) serving as a condenser.

    When the condition F is satisfied in the state 1, the state transits to the state 3. Condition F is that the difference (absolute value) between the inside air temperature Tr and the outside air temperature To is smaller than a predetermined temperature T1 (for example, T1 = 3 ° C.), the inside air temperature Tr is 45 ° C. or less, and the outside air temperature is 45 ° C. or less. This is true if That is, under such a condition where the difference between the outside air temperature To and the inside air temperature To is relatively small, there is a possibility that the liquid refrigerant accumulates in the adsorption heat exchanger (51, 52) on the evaporator side due to the detection error. is there. Therefore, under such conditions, the electric expansion valve (55) is fully closed to prevent the liquid refrigerant from moving to the adsorption heat exchanger (51, 52) on the evaporator side.

    In state 3, when condition G is satisfied, the state transitions to state 1. Condition G is satisfied by any of the following four. G-1) The inside air temperature Tr is not less than a value obtained by adding a predetermined temperature T2 (for example, T2 = 3.5 ° C.) to the outside air temperature To, and the current four-way selector valve (54) is in the second state. G-2) A value obtained by adding a predetermined temperature T2 (for example, T2 = 3.5 ° C.) to the inside air temperature Tr is equal to or lower than the outside air temperature To, and the current four-way selector valve (54) is in the first state. G-3) The inside air temperature Tr is higher than a predetermined temperature T3 (for example, T3 = 45 ° C.). G-4) The outside air temperature To is higher than a predetermined temperature T3 (for example, T3 = 45 ° C.).

    The above G-1) and G-2) mean that the temperature difference between the inside air temperature Tr and the outside air temperature To has become large enough not to be affected by the detection error. That is, if these conditions are satisfied, it can be determined that liquid refrigerant does not accumulate in the adsorption heat exchanger (51, 52) on the evaporator side by mistake, so the state transitions to state 1 and the electric expansion valve (55) Opened. Here, in the condition F, when the temperature difference between Tr and To is smaller than 3 ° C., the transition to the state 3 is made, whereas in the condition G-1 and the condition G-2, this temperature difference is 3.5 ° C. or more. Until state 1 is reached. That is, in the present embodiment, the temperature difference for transition from state 3 to state 1 (ie, T2) is made larger than the temperature difference for transition from state 1 to state 3 (ie, T1). By setting such a so-called differential, the liquid refrigerant is reliably prevented from moving to the adsorption heat exchanger (51, 52) on the evaporator side due to detection errors.

    The above G-3) and G-4) are caused by an increase in the volume of refrigerant accumulated in a predetermined line when the temperature of the air passing through the adsorption heat exchanger (51, 52) is extremely high. This is a condition for avoiding the internal pressure from exceeding the pressure resistance. Specifically, when the electric expansion valve (55) is in the closed state, for example, when the outside air temperature To becomes higher than 45 ° C., the temperature of the refrigerant in the line on the first adsorption heat exchanger (51) side increases, and this The volume of the refrigerant increases. As a result, the internal pressure of this line increases rapidly. Therefore, in this case, the state changes to the first state, and the electric expansion valve (55) is opened. Thereby, since the refrigerant circuit (50) is equalized, the rapid increase in the internal pressure of the line can be quickly eliminated. The same applies when the inside air temperature Tr becomes higher than 45 ° C.

    In state 2, if condition H is satisfied, the state transitions to state 3. Condition H is that the difference (absolute value) between the inside air temperature Tr and the outside air temperature To is smaller than a predetermined temperature T1 (for example, T1 = 3 ° C.), the inside air temperature Tr is 45 ° C. or less, and the outside air temperature is 45 ° C. or less. This is true if That is, when the temperature difference between Tr and To is relatively small, liquid refrigerant may be accumulated in the adsorption heat exchanger (51, 52) on the evaporator side due to detection error, so the state transitions to state 3. Fully close the electric expansion valve (55).

    In state 3, when condition I is satisfied, the state transitions to state 2. Condition I is satisfied by any of the following four. I-1) The inside air temperature Tr is not less than a value obtained by adding a predetermined temperature T2 (for example, T2 = 3.5 ° C.) to the outside air temperature To, and the current four-way selector valve (54) is in the first state. I-2) A value obtained by adding a predetermined temperature T2 (for example, T2 = 3.5 ° C.) to the inside air temperature Tr is equal to or lower than the outside air temperature To, and the current four-way selector valve (54) is in the second state. I-3) The inside air temperature Tr is higher than a predetermined temperature T3 (for example, T3 = 45 ° C.). I-4) The outside air temperature To is higher than a predetermined temperature T3 (for example, T3 = 45 ° C.). That is, in the condition I, similarly to the condition G, when the temperature difference between Tr and To is relatively large, or when the temperature of the inside air temperature Tr or the outside air temperature To is extremely high, the state transitions to the state 2 and the electric expansion valve (55) Is opened.

    In the state 1 and the state 2, the condition J is satisfied when the inside air temperature Tr and the outside air temperature To are extremely high (greater than 45 ° C.) and the temperature difference is less than 3 ° C. for one hour. That is, even when this condition is satisfied, there is a possibility that the refrigerant accumulates in the adsorption heat exchanger (51, 52) on the evaporator side. Therefore, in such a case, the refrigerant is prevented from accumulating in one of the adsorption heat exchangers (51, 52) by switching the air flow path.

    In state 3, if the temperature difference between the inside air temperature Tr and the outside air temperature To is smaller than 3 ° C. for one hour, the refrigerant may accumulate in the adsorption heat exchanger (51, 52) on the evaporator side. . Therefore, in such a case, the refrigerant is prevented from accumulating in one of the adsorption heat exchangers (51, 52) by switching the air flow path.

-Effect of the embodiment-
In the above embodiment, in the ventilation operation, when the difference between the inside air temperature Tr and the outside air temperature To is larger than the predetermined temperature T1 (second value), the electric expansion valve (55) is opened and the air having the lower temperature is It passes through the adsorption heat exchanger (51, 52) that becomes the condenser in the next humidity control operation. In this operation, since the temperature difference between the outdoor air and the indoor air is relatively large, due to the detection error of each temperature sensor (91, 93), the lower temperature air is absorbed by the adsorption heat exchanger on the evaporator side. (51, 52) can be reliably prevented from being supplied.

    In the ventilation operation, when the difference between the inside air temperature Tr and the outside air temperature To is smaller than the predetermined temperature T2 (first value), the electric expansion valve (55) is closed. In other words, in accordance with the detection error of each temperature sensor (91, 93), the electric expansion valve (55) under the condition that the magnitude relationship between the detected outside air temperature and the inside air temperature may be reversed from the actual magnitude relationship. ) Is fully closed. Thereby, the movement of the refrigerant between the two adsorption heat exchangers (51, 52) is blocked by the fully-expanded electric expansion valve (55). Accordingly, it is possible to prevent a large amount of liquid refrigerant from accumulating in the adsorption heat exchanger (51, 52) on the evaporator side due to the detection error of each temperature sensor (91, 93).

    As described above, in the ventilation operation of the present embodiment, it is possible to reliably prevent liquid refrigerant from being unevenly distributed in the adsorption heat exchanger (51, 52) on the evaporator side. A so-called liquid back in which the liquid refrigerant is sucked into the compressor (53) can be reliably avoided.

    In the above embodiment, the reference value T1 (= 3.5 ° C.) for opening the electric expansion valve (55) is larger than the reference value T2 (= 3.0) for closing the electric expansion valve (55). . This makes it difficult to open the electric expansion valve (55) in a state where the difference between the inside air temperature Tr and the outside air temperature To is around 3 ° C. Accordingly, it is possible to more reliably prevent the liquid refrigerant from moving to the adsorption heat exchanger (51, 52) on the evaporator side.

<< Other Embodiments >>
In the above embodiment, the reference value T1 and the reference value T2 may be set to the same value (for example, 3 ° C.).

    As described above, the present invention is useful for a humidity control apparatus.

DESCRIPTION OF SYMBOLS 10 Humidity control apparatus 40 Flow path switching mechanism 50 Refrigerant circuit 51 1st adsorption heat exchanger 52 2nd adsorption heat exchanger 55 Electric expansion valve (expansion valve)
80 controller (control unit)
91 Inside air temperature sensor (inside air temperature detector)
93 Outside temperature sensor (outside temperature detector)

Claims (3)

A humidity control device,
Compressor (53), refrigerant circuit (50) connected with two adsorption heat exchangers (51, 52) each carrying an adsorbent that adsorbs moisture, expansion valve (55), and four-way switching valve (54) When,
A flow path switching mechanism (40) for switching a flow path of air passing through the two adsorption heat exchangers (51, 52);
A ventilation operation in which the compressor (53) is stopped and outdoor air passes through one adsorption heat exchanger (51, 52) and indoor air passes through the other adsorption heat exchanger (51, 52); The compressor (53) is operated and one of the outdoor air and the indoor air passes through the adsorption heat exchanger (51, 52) as a condenser, and the other passes through the adsorption heat exchanger (51, 52) as an evaporator. A control unit (80) for controlling the refrigerant circuit (50) and the flow path switching mechanism (40) so as to perform a humidity control operation.
An outdoor temperature detector (93) that detects the temperature of the outdoor air as the outdoor temperature;
An inside air temperature detection unit (91) that detects the temperature of the room air as the inside air temperature,
In the ventilation operation, the control unit (80)
When the difference between the outside air temperature and the inside air temperature becomes larger than the first value, the air whose detection temperature is lower among the outdoor air and the room air is adjusted the next time while opening the expansion valve (55). Pass it through the adsorption heat exchanger (51, 52), which becomes the condenser during wet operation,
The humidity control device, wherein the expansion valve (55) is closed when a difference between the outside air temperature and the inside air temperature becomes smaller than a second value equal to or less than a first value. In claim 1,
When the expansion valve (55) is in the closed state in the ventilation operation, the control unit (80) is configured such that when at least one of the outside air temperature and the inside air temperature becomes higher than a predetermined temperature, the expansion valve (55) Humidity control device characterized by opening. In claim 1 or 2,
The humidity control apparatus, wherein the first value is larger than the second value.

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