JP2014070885A - Humidity controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent water droplets caused by dew condensation at the surfaces of adsorption agents of adsorption heat exchangers from being frozen at a humidity controller having two adsorption heat exchangers holding the adsorption agents thereon.SOLUTION: The humidity controller comprises a refrigerant circuit (20a) to which two adsorption heat exchangers (22, 24) are connected to perform a freezing cycle and a changing-over mechanism (25) for changing-over a refrigerant circulating direction at the refrigerant circuit (20a) for every prescribed time so as to adjust a humidity in a room. The humidity controller is provided with a condensing temperature control unit (101) for controlling a condensing temperature of the refrigerant at the refrigerant circuit (20a) to a temperature value more than a prescribed lower limit value when a temperature of air flowing in a regeneration side adsorption heat exchanger functioning as a condenser of the two adsorption heat exchangers (22, 24) is a predetermined temperature or lower.

Description

    The present invention relates to a humidity control apparatus that adjusts indoor humidity using an adsorption heat exchanger carrying an adsorbent.

    2. Description of the Related Art Conventionally, humidity control devices that adjust indoor humidity using an adsorption heat exchanger are known. Patent Document 1 discloses a humidity control apparatus of this type that adjusts indoor humidity using two adsorption heat exchangers carrying an adsorbent.

    The humidity control apparatus has a refrigerant circuit in which a compressor, an expansion mechanism, and two adsorption heat exchangers are connected and the refrigerant circulation direction is alternately switched every predetermined time. The two adsorption heat exchangers are alternately switched between an evaporator state and a condenser state by switching the refrigerant circulation direction. In addition, when the two adsorption heat exchangers are evaporators, the air is cooled by a refrigerant to adsorb moisture in the air to the adsorbent, and when they are condensers, the air is heated by the refrigerant. The moisture adsorbed by the adsorbent is released into the air. In other words, the two adsorption heat exchangers are alternately switched between the evaporator and the condenser, thereby adsorbing the moisture in the air to the adsorbent and releasing the moisture adsorbed on the adsorbent into the air. The regeneration operation for regenerating the adsorbent is performed alternately.

    In the humidity control apparatus, dehumidifying operation is performed by supplying the air dehumidified through the adsorption heat exchanger functioning as an evaporator into the room, and passing through the adsorption heat exchanger functioning as a condenser. Humidification operation is performed by supplying humidified air into the room.

JP 2004-294048 A

    By the way, when the air passing through the adsorption heat exchanger during the adsorption operation is cooled to a temperature below the dew point, dew condensation occurs on the surface of the adsorbent of the adsorption heat exchanger. Such water droplets due to condensation are usually heated by the refrigerant in the regeneration operation and released into the air, and are removed from the surface of the adsorbent of the adsorption heat exchanger.

    However, when the temperature of the air flowing into the adsorption heat exchanger that functions as a condenser is extremely low and the condensation temperature is low, the temperature of the air is not sufficiently raised in the adsorption heat exchanger that functions as a condenser. For this reason, water droplets condensed on the surface of the adsorbent during the adsorption operation remain without being released into the air even when the regeneration operation is switched, and may be frozen in the subsequent adsorption operation. Moisture that has been frozen in the adsorption operation is heated and melted by the refrigerant in the regeneration operation, but if the water is repeatedly frozen and thawed on the surface of the adsorbent, the adsorbent gradually deteriorates and the surface of the adsorption heat exchanger There was a risk of peeling.

    This invention is made | formed in view of this point, The objective is in the humidity control apparatus which has two adsorption | suction heat exchangers with which the adsorption agent was carry | supported, It is by condensation on the surface of the adsorption agent of an adsorption heat exchanger. It is to avoid freezing of water droplets.

    In the first invention, a compressor (21), an expansion mechanism (23), and two adsorption heat exchangers (22, 24) having adsorbents on the surface are connected, and the refrigerant circulates to perform a refrigeration cycle. A refrigerant circuit (20a) to perform, and a switching mechanism (25) for switching the refrigerant circulation direction in the refrigerant circuit (20a) at predetermined time intervals, and evaporating one of the two adsorption heat exchangers (22, 24). A humidity control device that adjusts the humidity of the room (S) by supplying the room (S) with air that has passed through the dehumidification side adsorption heat exchanger that functions as a condenser or the regeneration side adsorption heat exchanger that functions as a condenser. A condensing temperature control unit that controls the condensing temperature of the refrigerant in the refrigerant circuit (20a) to a temperature equal to or higher than a predetermined lower limit when the temperature of the air flowing into the regeneration side adsorption heat exchanger is equal to or lower than a predetermined temperature. (101).

    In the first invention, the refrigerant circulation direction in the refrigerant circuit (20a) is switched every predetermined time by the switching mechanism (25), and the two adsorption heat exchangers are alternately switched between the condenser and the evaporator. In the dehumidifying side adsorption heat exchanger that functions as an evaporator of the two adsorption heat exchangers, air is cooled by the refrigerant, and moisture in the air is adsorbed by the adsorbent. Thereby, air is dehumidified. On the other hand, in the regeneration side adsorption heat exchanger functioning as a condenser, air is heated by the refrigerant, and moisture adsorbed by the adsorbent is released into the air. As a result, the air is humidified and the adsorbent is regenerated so that the original moisture can be adsorbed.

    In the first invention, when the temperature of the air flowing into the regeneration side adsorption heat exchanger is equal to or lower than a predetermined temperature, the condensation temperature control unit (101) sets the condensation temperature of the refrigerant in the regeneration side adsorption heat exchanger. The temperature is controlled to be equal to or higher than a predetermined lower limit value. Therefore, even when the temperature of the air flowing into the regeneration side adsorption heat exchanger is low, the air is sufficiently heated by the refrigerant flowing through the regeneration side adsorption heat exchanger. Therefore, water droplets due to condensation generated on the surface of the adsorbent of the adsorption heat exchanger (22, 24) during the adsorption operation are released into the air heated by the refrigerant in the regeneration operation.

    In a second aspect based on the first aspect, the condensation temperature control unit (101) is configured such that the temperature of the air flowing into the regeneration side adsorption heat exchanger is equal to or lower than the predetermined temperature and the refrigerant circuit (20a) When the condensation temperature of the refrigerant is less than the lower limit value, the operating frequency of the compressor (21) is increased.

    In the second invention, the condensing temperature control unit (101) controls the compressor (21) when the temperature of the air flowing into the regeneration side adsorption heat exchanger and the condensing temperature of the refrigerant in the refrigerant circuit (20a) are low. It is configured to increase the operating frequency. When the operating frequency of the compressor (21) is increased, the refrigerant circulation amount in the refrigerant circuit (20a) is increased, so that the refrigerant condensation temperature in the refrigerant circuit (20a) is increased. Thereby, the condensation temperature of the refrigerant in the refrigerant circuit (20a) becomes a temperature equal to or higher than a predetermined lower limit value, and the air is sufficiently heated by the refrigerant flowing through the regeneration side adsorption heat exchanger.

    In a third aspect based on the first aspect, the condensing temperature control section (101) is configured such that the temperature of the air flowing into the regeneration side adsorption heat exchanger is equal to or lower than the predetermined temperature and the refrigerant circuit (20a) When the condensation temperature of the refrigerant is less than the lower limit value, the air volume of the air flowing into the regeneration side adsorption heat exchanger is reduced.

    In the third invention, the condensing temperature control unit (101) is configured so that the regeneration side adsorption heat exchanger is used when the temperature of the air flowing into the regeneration side adsorption heat exchanger and the refrigerant condensation temperature in the refrigerant circuit (20a) are low. It is comprised so that the air volume of the air which flows in may be reduced. When the amount of air flowing into the regeneration side adsorption heat exchanger is reduced, the amount of heat released from the refrigerant in the regeneration side adsorption heat exchanger is reduced, and the condensation temperature of the refrigerant in the refrigerant circuit (20a) is increased. Thereby, the condensation temperature of the refrigerant in the refrigerant circuit (20a) becomes a temperature equal to or higher than a predetermined lower limit value, and the air is sufficiently heated by the refrigerant flowing through the regeneration side adsorption heat exchanger.

    According to a fourth aspect of the present invention, in the third aspect of the invention, the dehumidifying side adsorption heat exchanger dehumidifies outdoor air and supplies it into the dry clean room at all times. The condensation temperature control unit (101) Is the regeneration side adsorption heat exchange when the temperature of the air flowing into the regeneration side adsorption heat exchanger is not more than the predetermined temperature and the refrigerant condensation temperature in the refrigerant circuit (20a) is less than the lower limit value. While reducing the air volume of the air flowing into the chamber, the air volume flowing into the dehumidifying side adsorption heat exchanger is kept constant without being reduced.

    Incidentally, as described above, in a humidity control apparatus having two adsorption heat exchangers (22, 24) that alternately perform an adsorption operation and a regeneration operation, the amount of air passing through the regeneration-side adsorption heat exchanger is usually The air volume is adjusted to be equal to the air volume passing through the dehumidifying side adsorption heat exchanger.

    In the fourth invention, when the temperature of the air flowing into the regeneration side adsorption heat exchanger and the condensation temperature of the refrigerant in the refrigerant circuit (20a) are low, the regeneration side adsorption heat exchange is performed by the condensation temperature control unit (101). Only the air volume of the air passing through the chamber was reduced, and the air volume of the air passing through the dehumidifying side adsorption heat exchanger was maintained without reduction. Thereby, since the air volume of the air passing through the regeneration side adsorption heat exchanger is reduced, the condensation temperature of the refrigerant in the refrigerant circuit (20a) increases, while the air volume of the air passing through the dehumidification side adsorption heat exchanger is reduced. As a result, the evaporation temperature hardly changes. Moreover, since the air volume of the air passing through the dehumidifying side adsorption heat exchanger is not reduced, the supply amount of the processing air (dehumidified air) to the dry clean room is kept constant.

    According to a fifth invention, in any one of the first to third inventions, a dehumidifying operation is performed in which outdoor air is dehumidified in the dehumidifying side adsorption heat exchanger and supplied to the room (S). Yes.

    In the fifth invention, the humidity control apparatus always performs a dehumidifying operation for dehumidifying outdoor air and supplying it to the room. As described above, in the humidity control apparatus that performs the dehumidifying operation at all times, the dehumidifying load becomes small when the temperature of the outdoor air is extremely low, such as in a cold region or in winter, so the refrigerant circulation amount in the refrigerant circuit (20a) is reduced. As a result, the condensation temperature is lowered. For this reason, water droplets that have condensed on the surface of the adsorbent of the adsorption heat exchanger (22, 24) during the adsorption operation remain without being released into the air even when the regeneration operation is switched, and are frozen in the subsequent adsorption operation. There is a greater risk that

    However, in the fifth invention, when the temperature of the air flowing into the regeneration side adsorption heat exchanger is equal to or lower than a predetermined temperature, the condensation temperature control unit (101) sets the condensation temperature of the refrigerant in the regeneration side adsorption heat exchanger. The temperature is controlled to be equal to or higher than a predetermined lower limit value. Therefore, water droplets due to dew condensation generated on the surface of the adsorbent of the dehumidifying side adsorption heat exchanger during the adsorption operation are released into the air heated by the refrigerant in the regeneration operation.

    According to the first invention, when the temperature of the air flowing into the regeneration side adsorption heat exchanger is equal to or lower than a predetermined temperature, the refrigerant condensing temperature in the regeneration side adsorption heat exchanger is controlled to a temperature equal to or higher than a predetermined lower limit value. The condensation temperature control unit (101) was provided. Therefore, even when the temperature of the air flowing into the regeneration side adsorption heat exchanger is low, the temperature of the air can be sufficiently raised by the refrigerant flowing through the regeneration side adsorption heat exchanger. Therefore, water droplets caused by condensation on the surface of the adsorbent of the adsorption heat exchanger (22, 24) during the adsorption operation are reliably removed from the surface of the adsorbent of the adsorption heat exchanger (22, 24) during the regeneration operation. be able to. Therefore, it is possible to avoid freezing of water droplets due to condensation on the surface of the adsorbent of the adsorption heat exchanger (22, 24).

    According to the second and third inventions, even if the temperature of the air flowing into the regeneration side adsorption heat exchanger and the refrigerant condensing temperature in the refrigerant circuit (20a) are low, the compressor (21) The refrigerant condensing temperature can be controlled to a temperature equal to or higher than a predetermined lower limit value only by increasing the operating frequency or reducing the air volume of the air flowing into the regeneration side adsorption heat exchanger. Thereby, the temperature of the air can be sufficiently raised by the refrigerant flowing through the regeneration side adsorption heat exchanger. Therefore, freezing of water droplets due to condensation on the surface of the adsorbent of the adsorption heat exchanger (22, 24) can be easily avoided.

    Further, according to the fourth aspect of the invention, the air flow of the air that normally passes through the dehumidification side adsorption heat exchanger and the regeneration side adsorption heat exchanger is made uniform, and the regeneration side adsorption heat exchange is performed by the condensation temperature control unit (101). If the temperature of the air flowing into the condenser and the refrigerant condensing temperature in the refrigerant circuit (20a) are low, only the air volume passing through the regeneration side adsorption heat exchanger is reduced and the dehumidification side adsorption heat exchanger is The air volume of the passing air was maintained without being reduced. Therefore, the condensation temperature can be raised without lowering the evaporation temperature of the refrigerant in the refrigerant circuit (20a). As a result, it is possible to easily avoid freezing of water droplets due to condensation on the surface of the adsorbent of the adsorption heat exchanger (22, 24) while suppressing an efficiency decrease due to an increase in the high and low pressure difference in the refrigerant circuit (20a). Can do. In addition, since the supply amount of the processing air (dehumidified air) to the dry clean room is kept constant, the dry clean room can be maintained in a positive pressure state where the pressure is higher than the outside.

    According to the fifth aspect of the invention, since the dehumidifying operation is always performed in the humidity control apparatus, when the outdoor air temperature is extremely low, dew condensation occurs on the surface of the adsorbent of the adsorption heat exchanger (22, 24). The possibility of freezing water droplets due to water is further increased. Because the condensation temperature control unit (101) is installed as described above, water droplets due to condensation freeze on the surface of the adsorbent of the adsorption heat exchanger (22, 24). You can avoid that.

It is a schematic block diagram which shows the whole structure of the humidity control apparatus of Embodiment 1, and has shown the state in which the dehumidification unit is in 1st operation | movement. It is a schematic block diagram which shows the whole structure of the humidity control apparatus of Embodiment 1, and has shown the state in which a dehumidification unit is in 2nd operation | movement. It is a piping system diagram of the refrigerant circuit of the 1st dehumidification unit of the humidity control apparatus of Embodiment 1. It is a piping system diagram of the refrigerant circuit of the 2nd dehumidification unit of the humidity control apparatus of Embodiment 1. It is a schematic block diagram which shows the whole structure of the humidity control apparatus of Embodiment 2. It is a piping system diagram of the refrigerant circuit of the humidity control apparatus according to the second embodiment.

    Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Embodiment 1 of the Invention
Embodiment of this invention is related with the humidity control apparatus (10) which adjusts the humidity of a room (S). In this embodiment, the room (S) subject to humidity adjustment is a dry clean room provided in a lithium battery production line where low dew point air is required, and the humidity control apparatus (10) uses outdoor air (OA). It is configured to dehumidify into low dew point air and to supply this air into the room as supply air (SA).

    As shown in FIG. 1, the humidity control apparatus (10) includes an air supply passage (40) that connects the outdoor and indoors, and an exhaust passage (50) that connects a midway portion of the air supply passage (40) and the outdoor. ). The air passage is constituted by the air supply passage (40) and the exhaust passage (50). In the air passage, a first dehumidifying unit (60) and a second dehumidifying unit (20) are provided from the outdoor air inlet side. Arranged in order. Although the detailed configuration of the two dehumidifying units (60, 20) will be described later, the first dehumidifying unit (60) is an external air cooling heat exchange connected to a first refrigerant circuit (70a) (see FIG. 3) described later. It has a vessel (61) and performs cooling dehumidification. On the other hand, the second dehumidifying unit (20) has two adsorption heat exchangers (22, 24) connected to a second refrigerant circuit (20a) described later and performs adsorption dehumidification (see FIG. 3).

    The air supply passage (40) has an inflow end that opens to the outside of the room, and an outflow end that opens in the room. The air supply passage (40) includes a first dehumidification unit (60), a second dehumidification unit (20), an air supply fan (63) for carrying air into the room, and a reheat heat exchanger (64 ) Are provided in order from the inflow end to the outflow end. The air supply passage (40) takes in outdoor air (OA), dehumidifies it in the first dehumidifying unit (60) and the second dehumidifying unit (20), and supplies it as indoor air (SA).

    The inflow end of the exhaust passage (50) is connected between the first dehumidifying unit (60) and the second dehumidifying unit (20) of the air supply passage (40), while the outflow end is open outside the room. . The exhaust passage (50) is provided with a second dehumidifying unit (20) and an exhaust fan (66) for releasing air to the outside of the room. The exhaust passage (50) takes in a part of the air in the air supply passage (40), regenerates the adsorbent adsorbed with moisture in the second dehumidification unit (20), and discharges it to the outside as exhaust (EA).

    The first dehumidifying unit (60) includes an outside air cooling heat exchanger (61) that cools and dehumidifies outdoor air, and a drain pan (62) that collects water condensed in the outside air cooling heat exchanger (61). Yes. The outdoor air cooling heat exchanger (61) is constituted by a fin-and-tube heat exchanger, is connected to a first refrigerant circuit (70a) described later, and functions as an evaporator to cool and dehumidify outdoor air. A drain pan (62) is provided in the vicinity of the outside air cooling heat exchanger (61). The drain pan (62) is constituted by, for example, a container provided below the outside air cooling heat exchanger (61) and having an upper surface opened, and receives water condensed in the outside air cooling heat exchanger (61).

    The second dehumidifying unit (20) includes a first adsorption heat exchanger (22), a second adsorption heat exchanger (24), a first channel switching unit (26), and a second channel switching unit ( 27) and. The first and second adsorption heat exchangers (22, 24) are formed by supporting an adsorbent such as a polymer sorbent or B-type silica gel on the surface of a fin-and-tube heat exchanger. The first and second adsorption heat exchangers (22, 24) are housed in separate housing chambers in a casing (not shown). The first and second flow path switching sections (26, 27) are constituted by a plurality of openable / closable dampers. When the four-way switching valve (25), which will be described later, is in the first state, the first and second flow path switching units (26, 27) are in the first flow state (the state indicated by the solid line in FIG. 1). When (25) is in the second state, the second distribution state (the state indicated by the solid line in FIG. 2) is set. In the first distribution state, the first flow path switching unit (26) and the second flow path switching unit (27) are both provided in the air supply passage (40) and the accommodation chamber (shown in the figure) of the second adsorption heat exchanger (24). The exhaust passage (50) and the accommodation chamber (not shown) of the first adsorption heat exchanger (22) are communicated with each other. On the other hand, in the second flow state, the first flow path switching unit (26) and the second flow path switching unit (27) are both in the supply passage (40) and the accommodation chamber of the first adsorption heat exchanger (22). (Not shown) and the exhaust passage (50) and the accommodation chamber (not shown) of the second adsorption heat exchanger (24) are connected.

    In the present embodiment, the first and second dehumidifying units (60, 20) are configured to have different temperature ranges suitable for dehumidification. Specifically, the cooling and dehumidification by the outside air cooling heat exchanger (61) of the first dehumidifying unit (60) is performed in the temperature range having a dew point of about 8 ° C. or higher, and the adsorption heat exchanger (22 , 24) is configured to be suitable for use in a temperature range with a dew point of about 10 ° C to -20 ° C.

<First refrigerant circuit>
As shown in FIG. 3, the outside air cooling heat exchanger (61) and the reheat heat exchanger (64) are connected to the first refrigerant circuit (70a). The first refrigerant circuit (70a) is a single refrigeration cycle type refrigerant circuit in which the refrigerant circulates through one closed circuit.

    A compressor (80) is connected to the first refrigerant circuit (70a). The compressor (80) is a rotary fluid machine such as a rotary type, a swing type, or a scroll type. The compressor (80) is configured as a variable capacity type whose operating frequency is adjusted by an inverter circuit.

    The discharge side of the compressor (80) branches into a first discharge line (71) and a second discharge line (72). The reheat heat exchanger (64) and the first expansion valve (82) are connected to the first discharge line (71) in order from the upstream side to the downstream side. A condensation pressure adjusting heat exchanger (83) and a second expansion valve (84) are connected to the second discharge line (72) in order from the upstream side toward the downstream side. A first outdoor fan (85) for blowing outdoor air is provided in the vicinity of the condensing pressure adjusting heat exchanger (83).

    The suction side of the compressor (80) branches into a first suction line (73) and a second suction line (74). The outside air cooling heat exchanger (61) is connected to the first suction line (73). A third expansion valve (87) and an evaporation pressure adjusting heat exchanger (88) are connected to the second suction line (74) in order from the upstream side to the downstream side. A second outdoor fan (89) for blowing outdoor air is provided in the vicinity of the evaporation pressure adjusting heat exchanger (88).

    One junction pipe (75) is connected between the outflow end of each discharge line (71, 72) and the inflow end of each suction line (73, 74). The merge pipe (75) is provided with a gas-liquid separator (79). The inflow end of the injection pipe (76) is connected to the gas phase portion of the gas-liquid separator (79). The outflow end of the injection pipe (76) is connected to the suction pipe of the compressor (80). The injection pipe (76) is provided with a fourth expansion valve (91).

    The reheat heat exchanger (64) and the condensation pressure adjustment heat exchanger (83) constitute a condenser in which the refrigerant dissipates heat to the air and condenses. The outside air cooling heat exchanger (61) and the evaporation pressure adjusting heat exchanger (88) constitute an evaporator in which the refrigerant absorbs heat from the air and evaporates. Each expansion valve (82, 84, 87, 91) mentioned above is an electronic expansion valve, for example, and constitutes a decompression mechanism for adjusting the pressure of the refrigerant.

<Second refrigerant circuit>
As shown in FIG. 4, the first adsorption heat exchanger (22) and the second adsorption heat exchanger (24) are connected to a second refrigerant circuit (20a). The second refrigerant circuit (20a) is a single refrigeration cycle type refrigerant circuit in which the refrigerant circulates through one closed circuit. In addition to the two adsorption heat exchangers (22, 24), a compressor (21), an expansion valve (23), and a four-way switching valve (25) are connected to the second refrigerant circuit (20a).

    The four-way switching valve (25) has first to fourth ports, the first port being the discharge side of the compressor (21), the second port being the suction side of the compressor (21), and the third port. The port is connected to the end of the first adsorption heat exchanger (22), and the fourth port is connected to the end of the second adsorption heat exchanger (24). The four-way switching valve (25) has a first state (state indicated by a solid line in FIG. 3) in which the first port and the third port communicate with each other and a second port and a fourth port communicate with each other, The four ports communicate with each other and can be switched to a second state (state indicated by a broken line in FIG. 3) in which the second port and the third port communicate.

    When the four-way selector valve (25) is switched to the first state, the second adsorption heat exchanger (24) functions as an evaporator and becomes a dehumidifying side adsorption heat exchanger that dehumidifies air, while the first adsorption heat exchange. The regenerator (22) functions as a condenser and serves as a regeneration side adsorption heat exchanger for regenerating the adsorbent. On the other hand, when the four-way switching valve (25) is switched to the second state, the first adsorption heat exchanger (22) functions as an evaporator to become a dehumidifying side adsorption heat exchanger that dehumidifies air, while the second adsorption The heat exchanger (24) functions as a condenser and becomes a regeneration side adsorption heat exchanger for regenerating the adsorbent. That is, in the four-way switching valve (25), the two adsorption heat exchangers (22, 24) provided in the second refrigerant circuit (20a) are alternately used as the dehumidification side adsorption heat exchanger and the regeneration side adsorption heat exchanger. A switching mechanism for switching the refrigerant circulation direction in the second refrigerant circuit (20a) is configured so as to be switched to.

<Sensor, controller>
The humidity control apparatus (10) is provided with various sensors and a controller (100) that performs various controls based on detection values from the various sensors.

    As shown in FIG. 1, the air supply passage (40) is provided with first to third air temperature sensors (11 to 13) and a humidity sensor (14) for detecting the temperature of the air. The first air temperature sensor (11) is provided on the downstream side of the outside air cooling heat exchanger (61) and detects the temperature of the air that has passed through the outside air cooling heat exchanger (61). A 2nd air temperature sensor (12) and a humidity sensor (14) are provided in the downstream of the 2nd flow-path switching part (27) of a 2nd dehumidification unit (20), and two adsorption heat exchangers (22,24) ) And the relative humidity of the air passing through the dehumidifying side adsorption heat exchanger functioning as an evaporator. The third air temperature sensor (13) is provided on the downstream side of the reheat heat exchanger (64) and detects the temperature of the air that has passed through the reheat heat exchanger (64).

    The exhaust passage (50) is provided with a fourth air temperature sensor (15) for detecting the temperature of the air. The fourth air temperature sensor (15) is provided on the upstream side of the first flow path switching unit (26) of the second dehumidification unit (20), and is a condenser of the two adsorption heat exchangers (22, 24). The temperature of the air flowing into the regeneration side adsorption heat exchanger that functions as

    As shown in FIG. 3, the first refrigerant circuit (70a) includes a high pressure sensor (95) for detecting a high pressure (condensation pressure) of the first refrigerant circuit (70a), and a low pressure (evaporation pressure). ) To detect a low pressure sensor (96). On the other hand, as shown in FIG. 4, the second refrigerant circuit (20a) is provided with a high pressure sensor (17) for detecting the high pressure (condensation pressure) of the second refrigerant circuit (20a).

    The controller (100) is configured to control the compressor (21, 80) in the first and second refrigerant circuits (20a, 70a) based on the detection values of the various sensors described above and various set values input by the user. The operation frequency, the opening degree of each expansion valve (23, 82, 84, 87, 91), the air flow rate of each fan (63, 66) and each outdoor fan (85, 89), etc. are controlled.

    Further, the controller (100) is configured so that the temperature Ta of the air flowing into the regeneration side adsorption heat exchanger of the first and second adsorption heat exchangers (22, 24) is equal to or lower than a predetermined temperature (eg, 0 ° C.). In addition, a condensing temperature control unit (101) for controlling the condensing temperature Tc of the second refrigerant circuit (20a) to a temperature equal to or higher than a predetermined lower limit value Tmin (for example, 10 ° C.) is provided. In the present embodiment, the condensing temperature control unit (101) determines that the temperature Ta of the air flowing into the regeneration side adsorption heat exchanger detected by the fourth air temperature sensor (15) is equal to or lower than a predetermined temperature (for example, 0 ° C.). When the condensation temperature Tc is lower than the lower limit value Tmin, the operating frequency of the compressor (21) is increased to control the condensation temperature Tc to a temperature equal to or higher than the lower limit value Tmin.

    In the present embodiment, the condensing temperature Tc of the second refrigerant circuit (20a) is calculated by the controller (100) based on the condensing pressure of the second refrigerant circuit (20a) detected by the high pressure sensor (17). Is done.

    In addition, the lower limit value Tmin indicates the amount of dew that adheres to the dehumidification side adsorption heat exchanger even when the temperature of the air flowing into the regeneration side adsorption heat exchanger is extremely low (for example, −10 ° C.). It is set to a temperature (for example, 10 ° C.) at which water droplets are not released and left in the air when they become the regeneration side adsorption heat exchanger.

-Driving action-
The operation of the humidity controller (10) will be described.

<Operation in the first refrigerant circuit>
During operation of the humidity control apparatus (10), the refrigerant circulates in the first refrigerant circuit (70a) to perform a vapor compression refrigeration cycle. At this time, the opening degree of the first expansion valve (82) and the fourth expansion valve (91) is adjusted as appropriate, and the second expansion valve (84) and the third expansion valve (87) are fully closed. Further, the first outdoor fan (85) and the second outdoor fan (89) are stopped.

    The refrigerant compressed by the compressor (80) is sent to the first discharge line (71) and flows through the reheat heat exchanger (64). In the reheat heat exchanger (64), the refrigerant dissipates heat to the air and condenses. The refrigerant condensed in the reheat heat exchanger (64) is depressurized to a low pressure by the first expansion valve (82), passes through the gas-liquid separator (79), and is sent to the first suction line (73). The opening of the first expansion valve (82) is controlled by the degree of superheat of the refrigerant on the suction side of the compressor (80).

    The refrigerant sent to the first suction line (73) flows through the outside air cooling heat exchanger (61). In the outdoor air cooling heat exchanger (61), the refrigerant absorbs heat from the air and evaporates. The refrigerant evaporated in the outside air cooling heat exchanger (61) is sucked into the compressor (80) and compressed.

    In the first refrigerant circuit (70a), the following control operations are appropriately executed in accordance with the operating conditions of the humidity controller (10).

    During the operation of the humidity control device (10), the controller (100) requires the required capacity Qc of the condenser (ie, the reheat heat exchanger (64)) and the evaporator (ie, the outside air cooling heat exchanger (61)). Is calculated based on the detected temperatures of the first air temperature sensor (11) and the third air temperature sensor (13).

    When the required capacity Qc on the condenser side is larger than the required capacity Qe on the evaporator side, the condensation pressure detected by the high-pressure sensor (95) reaches the target condensation pressure determined based on the required capacity Qc. Thus, the operating frequency of the compressor (80) is adjusted. As a result, the condensing pressure can be quickly reached the target condensing pressure, and the necessary capacity Qc can be ensured.

    On the other hand, when the compressor (80) is controlled so that the condensation pressure reaches the target value, the evaporation pressure may exceed the target evaporation pressure, and the required capacity Qe on the evaporator side may be insufficient. Therefore, in such a case, the second expansion valve (84) is opened at a predetermined opening. When the second expansion valve (84) is opened, the refrigerant on the discharge side of the compressor (80) flows through both the first discharge line (71) and the second discharge line (72), and condensing pressure adjustment heat exchange is performed. The refrigerant also condenses in the vessel (83). Then, the operating frequency of the compressor (80) increases so as to maintain the condensation pressure at the target condensation pressure. As a result, the evaporation pressure can be reduced to approach the target evaporation pressure.

    When the required capacity Qe on the evaporator side is larger than the required capacity Qc on the condenser side, the evaporation pressure detected by the low pressure sensor (96) becomes the target evaporation pressure determined based on the required capacity Qe. The operating frequency of the compressor (80) is adjusted to reach. Thereby, the required pressure Qe can be ensured by causing the evaporation pressure to quickly reach the target evaporation pressure.

    On the other hand, when the compressor (80) is controlled so that the evaporation pressure reaches the target value, the condensing pressure may be lower than the target condensing pressure, and the required capacity Qc on the condenser side may be insufficient. Therefore, in such a case, the third expansion valve (87) is opened at a predetermined opening. When the third expansion valve (87) is opened, the refrigerant on the suction side of the compressor (80) flows through both the first suction line (73) and the second suction line (74), and evaporating pressure adjustment heat exchange. The refrigerant also evaporates in the vessel (88). Then, the operating frequency of the compressor (80) increases so as to maintain the evaporation pressure at the target evaporation pressure. As a result, the condensation pressure can be raised to approach the target condensation pressure.

<Operation in the second refrigerant circuit>
During the operation of the humidity control apparatus (10), the refrigerant circulates in the second refrigerant circuit (20a) to perform a vapor compression refrigeration cycle. Specifically, the compressor (21) is operated, the expansion valve (23) is controlled to a predetermined opening degree, and the four-way switching valve (25) is alternately switched between the first state and the second state.

    When the four-way switching valve (25) is switched to the first state, the refrigerant compressed by the compressor (21) passes through the four-way switching valve (25) and flows through the first adsorption heat exchanger (22). In the first adsorption heat exchanger (22), a regeneration operation is performed in which the adsorbent is heated by the refrigerant, and moisture in the adsorbent is released to the air. The refrigerant radiated and condensed by the first adsorption heat exchanger (22) is depressurized by the expansion valve (23) and then flows through the second adsorption heat exchanger (24). In the second adsorption heat exchanger (24), an adsorption operation in which moisture in the air is adsorbed by the adsorbent is performed, and the adsorption heat generated at that time is imparted to the refrigerant. The refrigerant that has absorbed heat and evaporated in the second adsorption heat exchanger (24) is sucked into the compressor (21) and compressed.

    On the other hand, when the four-way switching valve (25) is switched to the second state, the refrigerant compressed by the compressor (21) passes through the four-way switching valve (25) and passes through the second adsorption heat exchanger (24). Flowing. In the second adsorption heat exchanger (24), the adsorbent is heated by the refrigerant, and a regeneration operation is performed in which moisture in the adsorbent is released to the air. The refrigerant radiated and condensed by the second adsorption heat exchanger (24) is depressurized by the expansion valve (23) and then flows through the first adsorption heat exchanger (22). In the first adsorption heat exchanger (22), an adsorption operation in which moisture in the air is adsorbed by the adsorbent is performed, and adsorption heat generated at that time is imparted to the refrigerant. The refrigerant that has absorbed heat and evaporated in the first adsorption heat exchanger (22) is sucked into the compressor (21) and compressed.

    In the above operation, the operating frequency of the compressor (21) is controlled by the controller (100) so that the humidity of the air that has passed through the dehumidifying side adsorption heat exchanger performing the adsorption operation becomes a desired humidity. . Specifically, the temperature T (° C.) and the relative humidity RH (% RH) of the air that has passed through the dehumidification side adsorption heat exchanger are detected by the second air temperature sensor (12) and the humidity sensor (14), Input to the controller (100). The controller (100) calculates the absolute humidity X (g / kg (DA)) based on the temperature T and the relative humidity RH of the air that has passed through the dehumidification side adsorption heat exchanger. And a controller (100) controls the operating frequency of a compressor (21) so that the calculated absolute humidity X may become below desired humidity. That is, when the absolute humidity X is higher than the desired humidity, the operating frequency of the compressor (21) is increased. On the other hand, when the absolute humidity X is equal to or lower than the desired humidity, the compressor (21) Maintain the operating frequency. Thereby, the air below the desired absolute humidity is supplied into the room (S).

<Operation of humidity control device>
Next, the operation of the humidity control apparatus (10) will be described. During the operation of the humidity control apparatus (10), the above-described operation is performed in the first and second refrigerant circuits (70a, 20a). In addition, each fan (63, 66) is driven with a predetermined air volume, and in the second dehumidifying unit (20), the first operation and the second operation are alternately performed every predetermined time (for example, at intervals of 270 seconds). .

    In the first operation, the four-way switching valve (25) of the second refrigerant circuit (20a) is switched to the first state, and the first and second flow path switching units (26, 27) provided in the air passage are the first. It becomes a distribution state. As a result, the second adsorption heat exchanger (24) serves as a dehumidifying side heat exchanger to dehumidify outdoor air, and at the same time, the first adsorption heat exchanger (22) serves as a regeneration side adsorption heat exchanger. Reproduce. On the other hand, in the second operation, the four-way switching valve (25) of the second refrigerant circuit (20a) is switched to the second state, and the first and second flow path switching units (26, 27) provided in the air passages. It will be in the 2nd distribution state. As a result, the first adsorption heat exchanger (22) serves as a dehumidification side heat exchanger to dehumidify outdoor air, and at the same time, the second adsorption heat exchanger (24) serves as a regeneration side adsorption heat exchanger and removes the adsorbent. Reproduce. The details will be described below.

    When each fan (63, 66) is driven, outdoor air (OA) flows into the air supply passage (40). This air is relatively hot and humid air. The air flowing through the air supply passage (40) passes through the outside air cooling heat exchanger (61) of the first dehumidifying unit (60) and flows through the inside of the outside air cooling heat exchanger (61) (70a). ). The condensed water generated from the air during cooling is collected in the drain pan (62). During the first operation, the air cooled and dehumidified by the outside air cooling heat exchanger (61) passes through the second adsorption heat exchanger (24) serving as the dehumidification side adsorption heat exchanger. In the air passing through the second adsorption heat exchanger (24), moisture in the air is adsorbed by the adsorbent, and the heat of adsorption generated at that time is absorbed by the refrigerant. In this way, the air passing through the second adsorption heat exchanger (24) is dehumidified. During the second operation, the air cooled and dehumidified by the outside air cooling heat exchanger (61) passes through the first adsorption heat exchanger (22) serving as the dehumidification side adsorption heat exchanger. Cooled and dehumidified.

    The adsorption heat generated when the moisture in the air in the air supply passage (40) is adsorbed by the adsorbent of each adsorption heat exchanger (22, 24) is the refrigerant flowing through each adsorption heat exchanger (22, 24). Given to. Moreover, since the air which flows through an air supply path (40) receives the cooling effect | action by a refrigerant | coolant, it is dehumidified and humidity falls and it cools and temperature also falls.

    The air dehumidified by the second dehumidifying unit (20) flows through the air supply passage (40), and after the temperature is adjusted by the reheat heat exchanger (64), is supplied indoors as the air supply (SA). . On the other hand, a part of the air in the room (S) is exhausted to the outside as exhaust (EA).

    In addition, a part of the air cooled and dehumidified by the outside air cooling heat exchanger (61) in the air supply passage (40) flows into the exhaust passage (50). During the first operation, the air flowing through the exhaust passage (50) passes through the first adsorption heat exchanger (22) of the second dehumidification unit (20). In the first adsorption heat exchanger (22), moisture is desorbed from the adsorbent into the air, and the adsorbent is regenerated. The air used for regeneration of the adsorbent in the first adsorption heat exchanger (22) flows through the exhaust passage (50) and is discharged to the outside as exhaust (EA). Further, during the second operation, the air flowing through the exhaust passage (50) is exhausted outside as the exhaust (EA) after regenerating the adsorbent of the second adsorption heat exchanger (24). Thus, in the present embodiment, a part of the outdoor air taken into the air supply passage (40) is used for regeneration of the adsorption heat exchanger (22, 24).

<Condensation freezing suppression operation>
By the way, when the air passing through the dehumidifying side adsorption heat exchanger functioning as an evaporator in the second refrigerant circuit (20a) is cooled to a temperature below the dew point, dew condensation occurs on the surface of the adsorbent of the dehumidifying side adsorption heat exchanger. Occurs. Water droplets due to such condensation are usually heated by the refrigerant and released into the air when the refrigerant circulation direction of the second refrigerant circuit (20a) is switched to function as a condenser, and are absorbed by the adsorption heat exchanger. Removed from the surface of the agent.

    However, when the temperature of the air flowing into the regeneration side adsorption heat exchanger functioning as the second refrigerant circuit (20a) condenser is extremely low and the condensation temperature of the second refrigerant circuit (20a) is low, the regeneration side In the adsorption heat exchanger, air is not sufficiently heated. For this reason, water droplets condensed on the surface of the adsorbent during the adsorption operation remain without being released into the air even when the regeneration operation is switched, and may be frozen in the subsequent adsorption operation.

    Therefore, when the temperature Ta of the air flowing into the regeneration side adsorption heat exchanger is equal to or lower than a predetermined temperature (for example, 0 ° C.) and the condensation temperature Tc becomes lower than the predetermined lower limit value Tmin, the controller (100) Performs condensation freezing suppression operation. The condensation freezing suppression operation is executed by the condensation temperature control unit (101).

    Specifically, the condensation temperature control unit (101) determines that the temperature Ta of the air flowing into the regeneration side adsorption heat exchanger detected by the fourth air temperature sensor (15) is equal to or lower than a predetermined temperature (for example, 0 ° C.). When the condensation temperature Tc calculated from the detected value of the high pressure sensor (17) is less than the lower limit value Tmin, the operating frequency of the compressor (21) is increased. When the operating frequency of the compressor (21) is increased, the refrigerant circulation amount in the second refrigerant circuit (20a) is increased, so that the refrigerant condensation temperature Tc in the second refrigerant circuit (20a) is increased.

    If the condensation temperature Tc is less than the lower limit Tmin even if the operating frequency of the compressor (21) is increased, the condensing temperature control unit (101) further increases the operating frequency of the compressor (21). . In this way, the condensation temperature control unit (101) increases the operating frequency of the compressor (21) until the condensation temperature Tc reaches a temperature equal to or higher than the lower limit value Tmin.

    By such an operation, the condensation temperature Tc is equal to or higher than the lower limit value Tmin when the temperature Ta of the air flowing into the regeneration side adsorption heat exchanger becomes equal to or lower than a predetermined temperature (for example, 0 ° C.) by the condensation temperature control unit (101). The temperature is controlled to be As a result, even when the temperature of the air flowing into the regeneration side adsorption heat exchanger is extremely low (for example, −10 ° C.), the water droplets of dew that adheres when becoming the dehumidification side adsorption heat exchanger are When it becomes an adsorption heat exchanger, it is heated by a relatively high temperature refrigerant and released into the air. Therefore, when it becomes a dehumidification side adsorption heat exchanger again, it does not freeze.

-Effect of the embodiment-
According to this embodiment, when the temperature Ta of the air flowing into the regeneration side adsorption heat exchanger is equal to or lower than a predetermined temperature, the refrigerant condensation temperature Tc in the regeneration side adsorption heat exchanger is set to a temperature equal to or higher than the predetermined lower limit value Tmin. A condensing temperature control unit (101) to be controlled was provided. Therefore, even when the temperature Ta of the air flowing into the regeneration side adsorption heat exchanger is low, the air can be sufficiently heated by the refrigerant flowing through the regeneration side adsorption heat exchanger. Therefore, water droplets caused by condensation on the surface of the adsorbent of the adsorption heat exchanger (22, 24) during the adsorption operation are reliably removed from the surface of the adsorbent of the adsorption heat exchanger (22, 24) during the regeneration operation. be able to. Therefore, it is possible to avoid freezing of water droplets due to condensation on the surface of the adsorbent of the adsorption heat exchanger (22, 24).

    Further, according to the present embodiment, even when the temperature Ta of the air flowing into the regeneration side adsorption heat exchanger and the refrigerant condensation temperature Tc in the second refrigerant circuit (20a) are low, the compressor (21) The refrigerant condensation temperature Tc can be controlled to a temperature equal to or higher than a predetermined lower limit value Tmin simply by increasing the operating frequency. Thereby, the temperature of the air can be sufficiently raised by the refrigerant flowing through the regeneration side adsorption heat exchanger. Therefore, freezing of water droplets due to condensation on the surface of the adsorbent of the adsorption heat exchanger (22, 24) can be easily avoided.

    Moreover, according to this embodiment, since the dehumidifying operation is always performed in the humidity control apparatus (10), the surface of the adsorbent of the adsorption heat exchanger (22, 24) when the outdoor air temperature is extremely low. The possibility of freezing water droplets due to dew condensation is further increased in this case, and the condensation temperature control unit (101) as described above is provided, so that water droplets due to dew condensation on the surface of the adsorbent of the adsorption heat exchanger (22, 24). Freezing can be avoided.

<< Embodiment 2 of the Invention >>
The second embodiment includes a second exhaust passage (51), a return air passage (58), a third dehumidification unit (30), and a return air cooling heat exchanger in the humidity control device (10) of the first embodiment. (67) is added. Below, only a different part from Embodiment 1 is demonstrated.

    The second exhaust passage (51) has an inflow end connected between the second dehumidifying unit (20) of the air supply passage (40) and the air supply fan (63), while an outflow end is connected to the exhaust passage (50). ) Is connected to the upstream side of the second dehumidification unit (20), and part of the air that has passed through the second dehumidification unit (20) of the supply passage (40) is removed from the second dehumidification unit (20) of the exhaust passage (50). ) To the upstream side. A third dehumidifying unit (30) is connected to the second exhaust passage (51).

    The return air passage (58) has an inflow end connected to a return air port communicating with the room (S), and an outflow end connected to the second dehumidifying unit (20) and the air supply fan (63) of the air supply passage (40). Connected between. The outflow end of the return air passage (58) is located upstream of the inflow end of the second exhaust passage (51). The return air passage (58) is provided with a ventilation fan (59) for sending room air to the air supply passage (40) and a return air cooling heat exchanger (67). The return air passage (58) returns room air (RA) to the air supply passage (40).

    The third dehumidifying unit (30) includes an adsorption rotor (31) and a regenerative heat exchanger (65). The adsorption rotor (31) is configured by carrying an adsorbent on the surface of a disk-shaped porous substrate. The adsorption rotor (31) is disposed across the air supply passage (40) and the second exhaust passage (51). Specifically, the adsorption rotor (31) is provided between the air supply fan (63) and the reheat heat exchanger (64) of the air supply passage (40), and the second exhaust passage (51). The regenerative heat exchanger (65) is provided so as to straddle the upstream side and the downstream side. The suction rotor (31) is driven by a drive mechanism (not shown) and is configured to rotate around the axis between the passages (40, 50).

    The adsorption rotor (31) flows upstream of the regenerative heat exchanger (65) of the first adsorption section (32) through which the air flowing through the air supply passage (40) passes and the second exhaust passage (51). A second adsorption part (33) through which air passes and a regeneration part (34) through which air passes after passing through the regeneration heat exchanger (65) of the second exhaust passage (51) are formed. The first adsorbing part (32) and the second adsorbing part (33) adsorb moisture in the air, and the regenerating part (34) releases moisture in the adsorbent into the air.

    The adsorption rotor (31) uses an adsorbent having properties different from those of the adsorption heat exchanger (22, 24). Specifically, the adsorption heat exchanger (22, 24) located on the upstream side operates the adsorbent at a high water vapor partial pressure (relative humidity), so that it does not use a polymer sorbent or B-type silica gel. While the adsorbent is used, the adsorbent such as A-type silica gel or zeolite is used for the adsorbent rotor (31) located on the higher stage side in order to operate the adsorbent with a low water vapor partial pressure (relative humidity). ing. That is, in the adsorption heat exchanger (22, 24), an adsorption isotherm in which the moisture content is large when the relative humidity is relatively high and the adsorption amount per unit increase of the relative humidity increases as the relative humidity of the air increases. The adsorption rotor (31) has a high moisture content when the relative humidity is relatively low, and the adsorption amount per unit increase of the relative humidity increases as the relative humidity of the air decreases. Adsorbents with isotherms have been selected.

    The regenerative heat exchanger (65) is constituted by a fin-and-tube heat exchanger, connected to the first refrigerant circuit (70a), functions as a condenser, and serves as an adsorption rotor (2) for the second exhaust passage (51). The air dehumidified in the second adsorption part (33) of 31) is heated.

    The return air cooling heat exchanger (67) is a fin-and-tube heat exchanger, is connected to the first refrigerant circuit (70a), functions as an evaporator, and flows through the return air passage (58). Cool down.

    In the present embodiment, the first to third dehumidifying units (60, 20, 30) are configured to have different temperature ranges suitable for dehumidification. Specifically, the cooling and dehumidification by the outside air cooling heat exchanger (61) of the first dehumidifying unit (60) is performed in the temperature range having a dew point of about 8 ° C. or higher, and the adsorption heat exchanger (22) of the second dehumidifying unit (20). , 24) is a dew point in the temperature range of about 10 ° C to -20 ° C, and dry dehumidification by the adsorption rotor (31) of the third dehumidification unit (30) is a temperature in which the dew point is about -20 ° C to -80 ° C. It is configured to be suitable for use in a range.

<First refrigerant circuit>
In the second embodiment, the configuration of the first refrigerant circuit is different from that of the first embodiment.

    In Embodiment 2, the regenerative heat exchanger (65) and the fifth expansion valve (81) are connected to the upstream side of the reheat heat exchanger (64) of the first discharge line (71). That is, in the first discharge line (71), the regeneration heat exchanger (65), the fifth expansion valve (81), the reheat heat exchanger (64), and the first An expansion valve (82) is connected. In addition, a return air cooling heat exchanger (67) is connected to the downstream side of the check valve (86) of the first suction line (73). That is, the outside air cooling heat exchanger (61), the check valve (86), and the return air cooling heat exchanger (67) are connected to the first suction line (73) in order from the upstream side to the downstream side. Has been. In Embodiment 2, a bypass pipe (77) that bypasses the outside air cooling heat exchanger (61) and the check valve (86) is connected to the first suction line (73), and the bypass pipe (77) is connected to the bypass pipe (77). Is provided with an electromagnetic on-off valve (92).

<Sensor, controller>
In the second embodiment, in addition to the first to fourth air temperature sensors (11 to 13, 15) and the humidity sensor (14) of the first embodiment, fifth and sixth air temperature sensors (18, 19) are provided. It has been. The fifth air temperature sensor (18) is provided downstream of the reheat heat exchanger (64) in the second exhaust passage (51) and detects the temperature of the air that has passed through the reheat heat exchanger (64). To do. The sixth air temperature sensor (19) is provided downstream of the return air cooling heat exchanger (67) in the return air passage (58) and detects the temperature of the air that has passed through the return air cooling heat exchanger (67). To do.

    In the second embodiment, the controller (100) includes the compressors (20a, 70a) in the first and second refrigerant circuits (20a, 70a) based on the detection values of the various sensors described above and the various setting values input by the user. 21,80), operating frequency of each expansion valve (23,81,82,84,87,91), air flow of each fan (63,66) and each outdoor fan (85,89), etc. To do.

    In the second embodiment, the controller (100) also sets the temperature Ta of the air flowing into the regeneration side adsorption heat exchanger of the first and second adsorption heat exchangers (22, 24) to a predetermined temperature (for example, In the case of 0 ° C. or lower, a condensing temperature control unit (101) for controlling the condensation temperature Tc of the second refrigerant circuit (20a) to a temperature equal to or higher than a predetermined lower limit value Tmin (for example, 10 ° C.) is provided. The configuration of the condensation temperature control unit (101) is the same as that of the first embodiment.

-Driving action-
The operation of the humidity controller (10) will be described.

<Operation in the first refrigerant circuit>
During operation of the humidity control apparatus (10), the refrigerant circulates in the first refrigerant circuit (70a) to perform a vapor compression refrigeration cycle. At this time, the opening degree of the fifth expansion valve (81), the first expansion valve (82), and the fourth expansion valve (91) is appropriately adjusted, and the second expansion valve (84) and the third expansion valve (87). And become fully closed. Further, the first outdoor fan (85) and the second outdoor fan (89) are stopped.

    The refrigerant compressed by the compressor (80) is sent to the first discharge line (71) and flows through the regenerative heat exchanger (65). In the regenerative heat exchanger (65), the refrigerant dissipates heat to the air and condenses. The refrigerant condensed in the regenerative heat exchanger (65) is depressurized to a slightly lower pressure by the fifth expansion valve (81) and then flows through the reheat heat exchanger (64). In the reheat heat exchanger (64), the refrigerant dissipates heat to the air and condenses. The refrigerant condensed in the reheat heat exchanger (64) is depressurized to a low pressure by the first expansion valve (82), passes through the gas-liquid separator (79), and is sent to the first suction line (73). The opening of the first expansion valve (82) is controlled by the degree of superheat of the refrigerant on the suction side of the compressor (80).

    The refrigerant sent to the first suction line (73) flows through the outside air cooling heat exchanger (61). In the outdoor air cooling heat exchanger (61), the refrigerant absorbs heat from the air and evaporates. The refrigerant evaporated in the outside air cooling heat exchanger (61) passes through the check valve (86) and flows through the return air cooling heat exchanger (67). In the return air cooling heat exchanger (67), the refrigerant absorbs heat from the air and evaporates. The refrigerant evaporated in the return air cooling heat exchanger (67) is sucked into the compressor (80) and compressed.

    In the first refrigerant circuit (70a), the following control operations are appropriately executed in accordance with the operating conditions of the humidity controller (10).

    During the operation of the humidity control device (10), the controller (100) requires the required capacity Qc on the condenser side (that is, the regeneration heat exchanger (65) and the reheat heat exchanger (64) side) and the evaporator side ( That is, the required capacity Qe of the outside air cooling heat exchanger (61) and the return air cooling heat exchanger (67) side is determined by the first air temperature sensor (11), the third air temperature sensor (13), and the fifth air. It is calculated based on the temperature detected by the temperature sensor (18) and the sixth air temperature sensor (19).

    When the required capacity Qc on the condenser side is larger than the required capacity Qe on the evaporator side, the condensation pressure detected by the high-pressure sensor (95) reaches the target condensation pressure determined based on the required capacity Qc. Thus, the operating frequency of the compressor (80) is adjusted. As a result, the condensing pressure can be quickly reached the target condensing pressure, and the necessary capacity Qc can be ensured.

    On the other hand, when the compressor (80) is controlled so that the condensation pressure reaches the target value, the evaporation pressure may exceed the target evaporation pressure, and the required capacity Qe on the evaporator side may be insufficient. Therefore, in such a case, the second expansion valve (84) is opened at a predetermined opening. When the second expansion valve (84) is opened, the refrigerant on the discharge side of the compressor (80) flows through both the first discharge line (71) and the second discharge line (72), and condensing pressure adjustment heat exchange is performed. The refrigerant also condenses in the vessel (83). Then, the operating frequency of the compressor (80) increases so as to maintain the condensation pressure at the target condensation pressure. As a result, the evaporation pressure can be reduced to approach the target evaporation pressure.

    When the required capacity Qe on the evaporator side is larger than the required capacity Qc on the condenser side, the evaporation pressure detected by the low pressure sensor (96) becomes the target evaporation pressure determined based on the required capacity Qe. The operating frequency of the compressor (80) is adjusted to reach. Thereby, the required pressure Qe can be ensured by causing the evaporation pressure to quickly reach the target evaporation pressure.

    On the other hand, when the compressor (80) is controlled so that the evaporation pressure reaches the target value, the condensing pressure may be lower than the target condensing pressure, and the required capacity Qc on the condenser side may be insufficient. Therefore, in such a case, the third expansion valve (87) is opened at a predetermined opening. When the third expansion valve (87) is opened, the refrigerant on the suction side of the compressor (80) flows through both the first suction line (73) and the second suction line (74), and evaporating pressure adjustment heat exchange. The refrigerant also evaporates in the vessel (88). Then, the operating frequency of the compressor (80) increases so as to maintain the evaporation pressure at the target evaporation pressure. As a result, the condensation pressure can be raised to approach the target condensation pressure.

    In the first refrigerant circuit (70a), the on-off valve (92) is opened when the temperature of the outdoor air (OA) detected by the outside air temperature sensor (not shown) is lower than the target evaporation pressure. As a result, the refrigerant can be sent to the return air cooling heat exchanger (67) by bypassing the outside air cooling heat exchanger (61).

    The operation in the second refrigerant circuit (20a) is the same as that in the first embodiment.

<Operation of humidity control device>
Next, the operation of the humidity control apparatus (10) will be described. During the operation of the humidity control apparatus (10), the above-described operation is performed in the first and second refrigerant circuits (70a, 20a). In addition, each fan (59, 63, 66) is driven at a predetermined air volume, and the second dehumidifying unit (20) performs the first operation and the first operation similar to those in the first embodiment every predetermined time (for example, at intervals of 270 seconds). Two operations are alternately performed.

    When each fan (63, 66) is driven, outdoor air (OA) flows into the air supply passage (40). The air flowing through the air supply passage (40) is cooled and dehumidified in the external air cooling heat exchanger (61) of the first dehumidifying unit (60) in the same manner as in the first embodiment, and the dehumidifying side of the second dehumidifying unit (20) Adsorption dehumidification is performed in the adsorption heat exchanger.

    The air dehumidified by the second dehumidifying unit (20) flows through the air supply passage (40) and passes through the first adsorption portion (32) of the adsorption rotor (31). As a result, the moisture in the air is adsorbed by the adsorbent of the adsorption rotor (31). The air dehumidified by the adsorption rotor (31) is supplied to the room as supply air (SA) after the temperature is adjusted by the reheat heat exchanger (64).

    Part of the air dehumidified by the second dehumidifying unit (20) flows into the second exhaust passage (51) and passes through the second adsorption portion (33) of the adsorption rotor (31). As a result, the moisture in the air is adsorbed by the adsorbent of the adsorption rotor (31). The second adsorption unit (33) is a stage in the middle of the movement of the regeneration unit (34) through which the high-temperature regeneration air has passed to the first adsorption unit (32). ) Flows, the second adsorbing portion (33) is cooled.

    The air dehumidified by the second adsorption part (33) of the adsorption rotor (31) flows through the second exhaust passage (51) and is heated by the regenerative heat exchanger (65). The heated air passes through the regeneration unit (34) of the adsorption rotor (31). As a result, moisture is desorbed from the adsorbent of the adsorption rotor (31) into the air, and the adsorbent is regenerated. The air used for the regeneration of the adsorption rotor (31) flows through the second exhaust passage (51), flows into the upstream side of the second dehumidification unit (20) in the exhaust passage (50), and is cooled to the outside air cooling heat exchanger. Merge with a part of the air cooled and dehumidified in (61). The combined air regenerates the adsorbent of the regeneration side adsorption heat exchanger of the second dehumidification unit (20), and then is discharged to the outside as exhaust (EA). Thus, in this embodiment, the air after regenerating the adsorption rotor (31) joins the exhaust passage (50) and is also used for regeneration of the adsorption heat exchanger (22, 24).

    On the other hand, a part of the air in the room (S) is exhausted to the outside as exhaust (EA). A part of the air in the room (S) flows into the return air passage (58). The air flowing through the return air passage (58) is cooled by the return air cooling heat exchanger (67) and then returned to the supply air passage (40). This return air is mixed with the air dehumidified by the second dehumidifying unit (20). Of the air dehumidified by the second dehumidifying unit (20) and the air returned from the room (S), the returned air has a lower humidity. For this reason, the air dehumidified by the second dehumidifying unit (20) is further reduced in humidity by being mixed with the return air. Thereby, the reproduction | regeneration capability in an adsorption | suction rotor (31) improves.

    The air flowing through the return air passage (58) is pushed into the air supply passage (40) by the ventilation fan (59). Here, in a configuration in which room air is sucked into the air supply passage (40) using only the air supply fan (63) without providing the ventilation fan (59), high humidity outdoor air is sucked from the outside of the duct to supply air (SA However, in this embodiment, air is pushed into the air supply passage (40) by the ventilation fan (59), so the inside of the system becomes positive pressure and sucks in high humidity outside air. Is prevented. Therefore, it is possible to prevent the humidity of the supply air (SA) from increasing.

    In the second embodiment, when the temperature Ta of the air flowing into the regeneration side adsorption heat exchanger is equal to or lower than a predetermined temperature (for example, 0 ° C.) and the condensation temperature Tc is lower than a predetermined lower limit value Tmin, the condensation temperature control is performed. Condensation freezing suppression operation similar to that in the first embodiment is performed by the unit (101).

    In the second embodiment as described above, the same effect as in the first embodiment can be obtained.

<< Embodiment 3 of the Invention >>
Embodiment 3 changes the structure of the condensing temperature control part (101) in the humidity control apparatus (10) of Embodiment 1 and Embodiment 2. FIG.

    In the third embodiment, the condensation temperature control unit (101) is configured such that the temperature Ta of the air flowing into the regeneration side adsorption heat exchanger is equal to or lower than a predetermined temperature (for example, 0 ° C.) and the condensation temperature Tc is less than the lower limit value Tmin. In this case, the air volume of the air flowing into the regeneration side adsorption heat exchanger is reduced by reducing the air volume of the exhaust fan (66). When the amount of air flowing into the regeneration side adsorption heat exchanger is reduced, the amount of heat released from the refrigerant in the regeneration side adsorption heat exchanger decreases, and the condensation temperature Tc of the refrigerant in the second refrigerant circuit (20a) increases. To do.

    If the condensation temperature Tc is lower than the lower limit value Tmin even if the air volume of the exhaust fan (66) is reduced, the condensation temperature control unit (101) further reduces the air volume of the exhaust fan (66). In this way, the condensing temperature control unit (101) reduces the air volume of the exhaust fan (66) until the condensing temperature Tc reaches a temperature equal to or higher than the lower limit value Tmin.

    By the way, in normal operation, the air volume of the exhaust fan (66) is adjusted to an air volume equal to the air volume of the air supply fan (63). However, in this dew condensation freezing control, the air volume of the air supply fan (63) is not reduced even if the air volume of the exhaust fan (66) is reduced, and is kept constant.

    Thus, also in the third embodiment, the condensation temperature Tc is determined by the condensation temperature control unit (101) when the temperature Ta of the air flowing into the regeneration side adsorption heat exchanger becomes equal to or lower than a predetermined temperature (for example, 0 ° C.). The temperature is controlled to be equal to or higher than the lower limit value Tmin. As a result, even when the temperature of the air flowing into the regeneration side adsorption heat exchanger is extremely low (for example, −10 ° C.), the water droplets of dew that adheres when becoming the dehumidification side adsorption heat exchanger are When it becomes an adsorption heat exchanger, it is heated by a relatively high temperature refrigerant and released into the air. Therefore, when it becomes a dehumidification side adsorption heat exchanger again, it does not freeze.

    According to the third embodiment, even if the temperature Ta of the air flowing into the regeneration side adsorption heat exchanger and the refrigerant condensation temperature Tc in the second refrigerant circuit (20a) are low, the regeneration side adsorption heat exchange. The refrigerant condensing temperature Tc can be controlled to a temperature equal to or higher than a predetermined lower limit value Tmin only by reducing the air volume flowing into the chamber, that is, the air volume of the exhaust fan (66). Thereby, the temperature of the air can be sufficiently raised by the refrigerant flowing through the regeneration side adsorption heat exchanger. Therefore, freezing of water droplets due to condensation on the surface of the adsorbent of the adsorption heat exchanger (22, 24) can be easily avoided.

    Incidentally, as described above, in the humidity control apparatus (10) having the two adsorption heat exchangers (22, 24) that alternately perform the adsorption operation and the regeneration operation, the air that normally passes through the regeneration-side adsorption heat exchanger. Is adjusted to an air volume equal to the air volume of the air passing through the dehumidifying side adsorption heat exchanger. That is, the air volume of the exhaust fan (66) is adjusted to an air volume equal to the air volume of the air supply fan (63).

    However, in the third embodiment, when the temperature Ta of the air flowing into the regeneration side adsorption heat exchanger and the refrigerant condensation temperature Tc in the second refrigerant circuit (20a) are low, the condensation temperature control unit (101) By reducing only the air volume passing through the regeneration side adsorption heat exchanger (the volume of exhaust fan (66)), the air volume passing through the dehumidification side adsorption heat exchanger (the volume of air supply fan (63)) is It was decided to maintain without reducing. As a result, by reducing the air volume of the air passing through the regeneration side adsorption heat exchanger, the refrigerant condensation temperature Tc in the second refrigerant circuit (20a) rises, while the air volume of the air passing through the dehumidification side adsorption heat exchanger. By maintaining without reducing the evaporation temperature, the evaporation temperature hardly changes.

    Therefore, according to Embodiment 3, the condensation temperature Tc can be raised without lowering the evaporation temperature of the refrigerant in the second refrigerant circuit (20a). As a result, it is possible to easily avoid freezing of water droplets due to condensation on the surface of the adsorbent of the adsorption heat exchanger (22, 24) while suppressing the decrease in efficiency due to the increase in the high and low pressure difference in the second refrigerant circuit (20a). can do.

    Moreover, according to Embodiment 3, since the air volume of the air which passes a dehumidification side adsorption heat exchanger is not reduced, the supply amount of the process air (dehumidification air) to the room | chamber (S) as a dry clean room is maintained constant. The Accordingly, it is possible to maintain the dry clean room in a positive pressure state where the pressure is higher than the outdoor pressure.

<< Other Embodiments >>
About the said embodiment, it is good also as the following structures.

    In each of the above embodiments, the condensation temperature Tc of the second refrigerant circuit (20a) is calculated based on the high pressure (condensation pressure) of the second refrigerant circuit (20a). However, the method for obtaining the condensation temperature Tc of the second refrigerant circuit (20a) is not limited to those of the above embodiments. For example, a thermistor may be attached to the two adsorption heat exchangers (22, 24) to detect the temperature of the regeneration side adsorption heat exchanger, and the condensation temperature Tc may be obtained from the temperature of the regeneration side adsorption heat exchanger. Moreover, since the temperature of the air that has passed through the regeneration side adsorption heat exchanger is usually equal to or lower than the condensation temperature Tc, the condensation temperature Tc is estimated based on the temperature of the air that has passed through the regeneration side adsorption heat exchanger. It is good. Specifically, the temperature of the air that has passed through the regeneration side adsorption heat exchanger by providing an air temperature sensor on the downstream side of the first flow path switching unit (26) of the second dehumidifying unit (20) of the exhaust passage (50). And the condensation temperature Tc of the second refrigerant circuit (20a) is estimated based on the temperature of the air that has passed through the regeneration side adsorption heat exchanger.

    In each of the above embodiments, not only a material that mainly adsorbs water vapor, such as silica gel or zeolite, but also a material that adsorbs and absorbs water vapor may be used as the adsorbent. Specifically, for example, an organic polymer material having hygroscopicity can be used as the adsorbent. In an organic polymer material used as an adsorbent, a plurality of polymer main chains having hydrophilic polar groups in the molecule are cross-linked with each other, and the plurality of polymer main chains cross-linked with each other form a three-dimensional structure. Forming. Such adsorbents swell by trapping (ie, absorbing moisture) water vapor. The mechanism by which the adsorbent swells by absorbing moisture is presumed as follows. In other words, when this adsorbent absorbs moisture, water vapor is adsorbed around the hydrophilic polar group, and the electric force generated by the reaction between the hydrophilic polar group and water vapor acts on the polymer main chain. As a result, the polymer main chain is deformed. Then, water vapor is taken into the gap between the deformed polymer main chains by capillary force, and when the water vapor enters, a three-dimensional structure composed of a plurality of polymer main chains swells, resulting in an increase in the volume of the adsorbent. .

    Thus, in the said adsorbent, both the phenomenon in which water vapor is adsorbed by the adsorbent and the phenomenon in which water vapor is absorbed by the adsorbent occur. That is, water vapor is sorbed on the adsorbent. Further, the water vapor captured by the adsorbent enters not only the surface of the three-dimensional structure composed of a plurality of polymer main chains cross-linked with each other but also into the interior thereof. As a result, a large amount of water vapor is trapped in this adsorbent as compared with zeolite that only adsorbs water vapor on the surface.

    The adsorbent shrinks by releasing water vapor (that is, moisture release). In other words, when this adsorbent dehydrates, the amount of water trapped in the gap between the polymer main chains decreases, and the shape of the three-dimensional structure composed of a plurality of polymer main chains is based on By returning, the volume of the adsorbent decreases.

    The material used as the adsorbent is not limited to the above-described material as long as it swells by absorbing moisture and contracts by releasing moisture. For example, an ion-exchange resin having hygroscopicity may be used. Good.

    In each embodiment, the humidity controller (10) is configured to always perform a dehumidifying operation in which the outdoor air is dehumidified in the dehumidifying side adsorption heat exchanger and supplied into the dry clean room. (10) may be not only a dehumidifying operation, but also a humidifying operation in which outdoor air is humidified in a reheat-side adsorption heat exchanger and supplied indoors. Also, during the humidification operation, the condensation temperature control unit (101) performs the condensation freezing suppression control, so that even if the temperature Ta of the air flowing into the regeneration side adsorption heat exchanger is extremely low, the regeneration is performed. The air can be sufficiently heated by the refrigerant flowing through the side adsorption heat exchanger. Therefore, freezing of water droplets due to condensation on the surface of the adsorbent of the adsorption heat exchanger (22, 24) can be easily avoided.

    In Embodiment 1, the humidity controller (10) may not include the first dehumidifying unit (60) and the reheat heat exchanger (64). The exhaust passage (50) may be configured to exhaust air from the room to the outside.

    In the second embodiment, an electric heater or a steam heater may be used instead of the regenerative heat exchanger (65) of the first refrigerant circuit (70a).

    In the second embodiment, an air cooler may be provided between the second dehumidifying unit (20) and the third dehumidifying unit (30) to cool the air.

    In the second embodiment, the return air passage (58) for returning the room air (RA) to the air supply passage (40) is provided, but the return air passage (58) is not necessarily provided.

    Moreover, in the said Embodiment 2, a dehumidification unit is a 1st dehumidification unit (60) and an existing system provided with a 3rd dehumidification unit (30). 60) and an optional system that can be connected between the third dehumidifying unit (30). Then, the second dehumidifying unit (22, 24) having the adsorption heat exchanger (22, 24) is added to the conventional two-stage system consisting of the outside air cooling heat exchanger (61) and the adsorption rotor (31). 20) can be installed to realize energy saving of existing systems.

    In addition, the above embodiment is an essentially preferable illustration, Comprising: It does not intend restrict | limiting the range of this invention, its application thing, or its use.

    As described above, the present invention is useful for a humidity control apparatus that adjusts indoor humidity using an adsorption heat exchanger carrying an adsorbent.

10 Humidity control device
20a Second refrigerant circuit (refrigerant circuit)
21 Compressor
22 First adsorption heat exchanger
23 Expansion valve (expansion mechanism)
24 Second adsorption heat exchanger
25 Four-way switching valve (switching mechanism)
100 Controller 101 Condensation temperature controller
S room

Claims (5)

A refrigerant circuit (20a) in which a compressor (21), an expansion mechanism (23), and two adsorption heat exchangers (22, 24) provided with an adsorbent on the surface are connected to circulate refrigerant to perform a refrigeration cycle When,
A switching mechanism (25) for switching the refrigerant circulation direction in the refrigerant circuit (20a) every predetermined time,
Air that has passed through the dehumidification side adsorption heat exchanger functioning as an evaporator or the regeneration side adsorption heat exchanger functioning as a condenser of the two adsorption heat exchangers (22, 24) is supplied into the room (S). A humidity control device for adjusting the humidity of the room (S),
A condensing temperature control unit (101) for controlling the condensing temperature of the refrigerant in the refrigerant circuit (20a) to a temperature equal to or higher than a predetermined lower limit when the temperature of the air flowing into the regeneration side adsorption heat exchanger is equal to or lower than a predetermined temperature. A humidity control device comprising: In claim 1,
When the temperature of the air flowing into the regeneration side adsorption heat exchanger is not more than the predetermined temperature and the condensation temperature of the refrigerant in the refrigerant circuit (20a) is less than the lower limit value, the condensation temperature control unit (101) Furthermore, the humidity control apparatus characterized by increasing the operating frequency of the compressor (21). In claim 1,
When the temperature of the air flowing into the regeneration side adsorption heat exchanger is not more than the predetermined temperature and the condensation temperature of the refrigerant in the refrigerant circuit (20a) is less than the lower limit value, the condensation temperature control unit (101) Further, the humidity control apparatus is configured to reduce an air volume of air flowing into the regeneration side adsorption heat exchanger. In claim 3,
It is configured to always perform a dehumidifying operation in which outdoor air is dehumidified in the dehumidifying side adsorption heat exchanger and supplied into a dry clean room,
When the temperature of the air flowing into the regeneration side adsorption heat exchanger is not more than the predetermined temperature and the condensation temperature of the refrigerant in the refrigerant circuit (20a) is less than the lower limit value, the condensation temperature control unit (101) In addition, the air volume flowing into the regeneration side adsorption heat exchanger is reduced while the air volume flowing into the dehumidification side adsorption heat exchanger is maintained constant without being reduced. Humidity control device. In any one of Claims 1 thru | or 3,
A humidity control apparatus configured to always perform a dehumidifying operation in which outdoor air is dehumidified in the dehumidifying side adsorption heat exchanger and supplied to the room (S).

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