Ventilation system

Abstract

To suppress a waste drying operation.SOLUTION: A ventilation device 10 includes: an air supply passage 31 in which air to be supplied from an outdoor space SP1 to an indoor space SP2 flows; an air exhaust passage 32 in which air to be discharged from the indoor space SP2 to the outdoor space SP1 flows; an adjustment section 12 that is provided in the middle of the air supply passage 31 and the air exhaust passage 32 and supplies heat or moisture recovered from the air flowing in one of the air supply passage 31 and the air exhaust passage 32 to the air flowing in the other of the air supply passage 31 and the air exhaust passage 32; a bypass passage 33 that communicates between the outdoor space SP1 and the indoor space SP2 without passing through the adjustment section 12; a first opening / closing mechanism 15 provided in the bypass passage 33 to open / close the bypass passage 33; and a control section 17 that executes a drying operation for drying a first surface 15a when determining that a first condition that is a condition enabling dew formation to be caused on the first surface 15a on the high-temperature side of the first opening / closing mechanism 15 is satisfied.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present disclosure relates to a ventilation device.

Background Art

[0002] When ventilating an indoor space, a ventilation device that adjusts the air, such as humidity control or heat exchange, is known. Conventionally, such a ventilation device may be provided with a bypass passage for simple ventilation in addition to a passage for adjusting the air. For example, Patent Document 1 discloses a ventilation device including a humidity control unit that humidifies the outside air taken into the casing from the outside air intake, a bypass passage that supplies the outside air taken in from the outside air intake to the room without passing through the humidity control unit, and an opening / closing member that opens and closes the bypass passage.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The opening / closing member of the bypass passage is likely to condensate because, for example, during the dehumidifying ventilation operation in the humidity control unit, it is cooled by the air dehumidified and cooled in the adsorption heat exchanger. When condensation occurs on the opening / closing member, it is necessary to execute a drying operation that temporarily stops the humidity control operation in the ventilation device to dry the opening / closing member.

[0005] In a conventional ventilation device, for example, after continuously executing the dehumidifying ventilation operation for a predetermined set time (for example, 12 hours), a drying operation for a fixed time (for example, 1 hour) is uniformly executed. Therefore, even when condensation does not actually occur on the opening / closing member, the ventilation device executes the drying operation unnecessarily, and problems such as the air in the indoor space not being properly adjusted during that time or wasteful power consumption for the drying operation occurring.

[0006] This disclosure was made in consideration of the above-mentioned issues and aims to suppress unnecessary drying operations. [Means for solving the problem]

[0007] (1) The ventilation device of the present disclosure comprises: an air supply passage through which air supplied from an outdoor space to an indoor space flows; an exhaust passage through which air discharged from the indoor space to the outdoor space flows; an adjustment unit provided in the middle of the air supply passage and the exhaust passage, which supplies heat or moisture recovered from the air flowing through one of the air supply passage and the exhaust passage to the air flowing through the other of the air supply passage and the exhaust passage; a bypass passage that connects the outdoor space and the indoor space without passing through the adjustment unit; a first opening / closing mechanism provided in the bypass passage for opening and closing the bypass passage; and a control unit that performs a drying operation to dry the first surface when it is determined that a first condition is met, which is a condition under which condensation can occur on the first surface on the high-temperature side of the first opening / closing mechanism.

[0008] The control unit executes a drying operation when it determines that condensation may occur on the first surface of the first opening / closing mechanism on the high-temperature side. This prevents unnecessary drying operations.

[0009] (2) The first condition includes the surface temperature of the first surface being below the dew point temperature of the air adjacent to the surface.

[0010] When the surface temperature falls below the dew point temperature, there is a high risk of condensation forming on the first surface of the first opening / closing mechanism on the high-temperature side. Therefore, the control unit can suppress unnecessary drying operations by performing a drying operation to dry the first surface only in such cases.

[0011] (3) The control unit obtains the surface temperature based on the outlet temperature of the air supplied from the air supply passage into the room space.

[0012] By configuring it in this way, the detection unit for detecting surface temperature can be omitted, thereby reducing the cost of installing the detection unit.

[0013] (4) The control unit executes the drying operation when the cumulative amount of condensation on the first surface, calculated based on the difference between the dew point temperature and the surface temperature, exceeds a predetermined amount.

[0014] By configuring the system in this way, drying operations can be performed more appropriately according to the condensation conditions, thereby reducing unnecessary drying operations.

[0015] (5) When the surface temperature falls below the dew point temperature, the control unit shortens the drying time for performing the drying operation as the difference between the dew point temperature and the surface temperature or the statistical value of the difference becomes smaller.

[0016] By configuring it in this way, the drying time can be shortened depending on the condensation situation, thereby suppressing unnecessary drying operations.

[0017] (6) The first condition includes the temperature of the air adjacent to the second surface of the first opening / closing mechanism opposite to the first surface being below the dew point temperature of the air adjacent to the surface by a predetermined threshold.

[0018] If the temperature of the air adjacent to the second surface falls below the dew point temperature by a threshold, there is a high risk of condensation occurring on the first surface. Therefore, the control unit can suppress unnecessary drying operations by performing a drying operation to dry the first surface only in such cases.

[0019] (7) The control unit executes the drying operation when the cumulative time obtained by accumulating the time that satisfies the first condition becomes a predetermined time or more.

[0020] As long as the first condition is not met, the cumulative time does not increase, and therefore the drying operation is not performed. By configuring it in this way, unnecessary drying operations can be further suppressed.

[0021] (8) When a predetermined time has elapsed since the time when it is determined that the first condition is satisfied, the control unit executes the drying operation.

[0022] By configuring in this way, the control unit can omit the count processing of the integration time, so the processing load in the control unit can be reduced.

[0023] (9) The control unit can switch between a first operation of performing ventilation through the air supply passage and the exhaust passage and a second operation of performing ventilation through the bypass passage, and the drying operation is the second operation.

[0024] By configuring in this way, the first opening / closing mechanism can be dried in parallel with the ventilation of the indoor space.

Brief Description of the Drawings

[0025] [Figure 1] It is a plan view schematically showing the internal configuration of the ventilation device according to the embodiment. [Figure 2] It is a plan view schematically showing the internal configuration of the ventilation device according to the embodiment. [Figure 3] It is a side view schematically showing the internal configuration of the ventilation device as viewed from arrow III in FIG. 1. [Figure 4] It is a side view schematically showing the internal configuration of the ventilation device as viewed from arrow IV in FIG. 1. [Figure 5] It is a piping system diagram showing the adjustment unit according to the embodiment. [Figure 6] It is a piping system diagram showing the adjustment unit according to the embodiment. [Figure 7] It is an explanatory diagram showing the air flow in the drying operation according to the embodiment. [Figure 8] It is an explanatory diagram showing the air flow in the drying operation according to the embodiment. [Figure 9] It is a flowchart showing the control method according to the embodiment. [Figure 10]This is a subroutine showing the surface temperature acquisition process according to the embodiment. [Figure 11] This is a plan view showing the first opening / closing mechanism according to the embodiment. [Figure 12] This graph shows the relationship between the difference between the dew point temperature and the surface temperature and various other values. [Figure 13] This is a schematic plan view showing the internal configuration of the ventilation device in the modified configuration. [Modes for carrying out the invention]

[0026] The embodiments of this disclosure will be described below with reference to the attached drawings.

[0027] [Embodiment] [Overall configuration of ventilation system 10] Figures 1 and 2 are schematic plan views showing the internal configuration of the ventilation device 10 according to the embodiment. Figure 3 is a schematic side view showing the internal configuration of the ventilation device 10 as seen from arrow III in Figure 1, and Figure 4 is a schematic side view showing the internal configuration of the ventilation device as seen from arrow IV in Figure 1.

[0028] Figures 1 to 4 are accompanied by an XYZ Cartesian coordinate system for illustrative purposes. In the following explanation, the Z direction is defined as the up and down direction, with the positive side of the Z direction referred to as the upper side and the negative side as the lower side. Note that these directions do not necessarily have to coincide with the direction in which the ventilation device 10 is installed in the facility. For example, the Y direction may be the up and down direction.

[0029] The ventilation device 10 is a device that ventilates the indoor space SP2 while controlling humidity using a heat pump desiccant system. The ventilation device 10 is installed, for example, in the ceiling space of the room that forms the indoor space SP2. The ventilation device 10 comprises a casing 11 containing various paths 31 to 33, an adjustment unit 12, a supply fan 13, an exhaust fan 14, a first opening / closing mechanism 15, a second opening / closing mechanism 16, a control unit 17, and various sensors 61 to 66. The casing 11 houses these parts 12 to 17 and 61 to 66.

[0030] Refer to Figures 1 and 2. The casing 11 is formed in the shape of a rectangular, flattened rectangular box. The casing 11 has an outside air inlet 21 for taking in outside air (OA) from the outdoor space SP1, an air supply outlet 22 for blowing in supply air (SA) into the indoor space SP2, a return air inlet 23 for taking in return air (RA) from the indoor space SP2, and an exhaust outlet 24 for blowing out exhaust air (EA) into the outdoor space SP1. The outside air inlet 21 and the return air inlet 23 are formed, for example, on the same plane of the casing 11.

[0031] The casing 11 includes a first partition wall 11a and a second partition wall 11b. As shown in Figures 3 and 4, the first partition wall 11a divides the space within the casing 11 into an upper space SP3 and a lower space SP4. The second partition wall 11b divides the upper space SP3 into an outdoor side and an indoor side, and also divides the lower space SP4 into an outdoor side and an indoor side. The casing 11 includes an air supply passage 31, an exhaust passage 32, and a bypass passage 33.

[0032] The air supply passage 31 is a passage through which air supplied from the outdoor space SP1 to the indoor space SP2 flows. The air supply passage 31 connects the outdoor air intake 21 and the air supply outlet 22 via the adjustment unit 12. The air supply passage 31 includes a first air supply passage 31a located on the outdoor side of the adjustment unit 12 and a second air supply passage 31b located on the indoor side of the adjustment unit 12. The first air supply passage 31a is formed in the lower space SP4, and the second air supply passage 31b is formed in the upper space SP3. That is, when the air supply passage 31 passes through the adjustment unit 12 from the outdoor side to the indoor side, it moves from the lower space SP4 to the upper space SP3.

[0033] The exhaust passage 32 is a passage through which air flows from the indoor space SP2 to the outdoor space SP1. The exhaust passage 32 connects the return air intake 23 and the exhaust outlet 24 via the adjustment unit 12. The exhaust passage 32 includes a first exhaust passage 32a located on the indoor side of the adjustment unit 12 and a second exhaust passage 32b located on the outdoor side of the adjustment unit 12. The first exhaust passage 32a is formed in the upper space SP3, and the second exhaust passage 32b is formed in the lower space SP4. That is, when the exhaust passage 32 passes through the adjustment unit 12 from the indoor side to the outdoor side, it moves from the upper space SP3 to the lower space SP4.

[0034] The first exhaust passage 32a is located above the first supply passage 31a via the first partition wall 11a. The second exhaust passage 32b is located below the second supply passage 31b via the first partition wall 11a. In other words, both the supply passage 31 and the exhaust passage 32 cross each other vertically while directing airflow to the negative side in the X direction.

[0035] The bypass passage 33 is a passage that connects the outdoor space SP1 and the indoor space SP2 without passing through the adjustment unit 12. The bypass passage 33 includes a first opening 25 that is open to the first air supply passage 31a and a second opening 26 that is open to the second air supply passage 31b.

[0036] The adjustment unit 12 is a unit that generates supply air by adjusting the humidity of the outside air, and specifically, it is a unit that executes a vapor compression type refrigeration cycle by circulating a refrigerant. The adjustment unit 12 is located near the center of the casing 11 in the X direction and, together with the second partition wall 11b, divides the upper space SP3 and the lower space SP4 into an outdoor side and an indoor side. The adjustment unit 12 includes a first heat exchanger 51 and a second heat exchanger 52. The first heat exchanger 51 and the second heat exchanger 52 are arranged side by side, for example, in the Y direction.

[0037] The air supply fan 13 is located near the air supply outlet 22. The air supply fan 13 is, for example, a sirocco fan and rotates based on control commands from the control unit 17. When the air supply fan 13 rotates, air from the outdoor space SP1 (outside air) is drawn into the casing 11 from the outside air intake 21 and blown out from the air supply outlet 22 through the air supply passage 31 or the bypass passage 33.

[0038] The exhaust fan 14 is located near the exhaust outlet 24. The exhaust fan 14 is, for example, a sirocco fan and rotates based on control commands from the control unit 17. When the exhaust fan 14 rotates, air (return air) from the indoor space SP2 is drawn into the casing 11 from the return air intake 23, passes through the exhaust passage 32, and is blown out from the exhaust outlet 24.

[0039] The first opening / closing mechanism 15 is provided in the bypass passage 33 and opens and closes the bypass passage 33 based on a control command from the control unit 17. The first opening / closing mechanism 15 is, for example, a damper. When the first opening / closing mechanism 15 is in the closed state (shown by the solid line in Figure 1), no airflow is formed in the bypass passage 33 from the outdoor space SP1 to the indoor space SP2. When the first opening / closing mechanism 15 is in the open state (shown by the dashed line in Figure 1), airflow is permitted in the bypass passage 33 from the outdoor space SP1 to the indoor space SP2.

[0040] The second opening / closing mechanism 16 is provided in the air intake passage 31 and the exhaust passage 32, and controls the communication between the air intake passage 31 and the exhaust passage 32 and the adjustment unit 12 based on control commands from the control unit 17. The second opening / closing mechanism 16 includes a plurality of (eight in this embodiment) dampers 41 to 48. These dampers 41 to 48 open and close independently based on control commands from the control unit 17.

[0041] As shown in Figure 1, damper 41 is provided between the first air supply passage 31a and the first heat exchanger 51. Damper 42 is provided between the first air supply passage 31a and the second heat exchanger 52. Damper 43 is provided between the second air supply passage 31b and the first heat exchanger 51. Damper 44 is provided between the second air supply passage 31b and the second heat exchanger 52.

[0042] As shown in Figure 2, damper 45 is provided between the first exhaust passage 32a and the first heat exchanger 51. Damper 46 is provided between the first exhaust passage 32a and the second heat exchanger 52. Damper 47 is provided between the second exhaust passage 32b and the first heat exchanger 51. Damper 48 is provided between the second exhaust passage 32b and the second heat exchanger 52.

[0043] The control unit 17 includes a processor 17a and a memory 17b. The processor 17a includes, for example, one or more CPUs (Central Processing Units). The processor 17a may also be a GPU (Graphics Processing Unit). The control unit 17 performs various calculations and processes based on the program contained in the memory 17b, thereby executing the various controls described below.

[0044] The processor 17a may also be an integrated circuit such as a CPLD (Complex Programmable Logic Device), FPGA (Field-Programmable Gate Array), or ASIC (Application Specific Integrated Circuit). In this case, the processor 17a performs various calculations and processes based on a pre-written program.

[0045] [Configuration of the adjustment unit 12] Figures 5 and 6 are piping diagrams showing the adjustment unit 12. The adjustment unit 12 is installed in the middle of the air supply passage 31 and the exhaust passage 32, and is a unit that supplies moisture recovered from the air flowing through one of the air supply passages 31 and exhaust passage 32 to the air flowing through the other air supply passage 31 and exhaust passage 32.

[0046] The adjustment unit 12 comprises a first heat exchanger 51, a second heat exchanger 52, a compressor 55, a switching mechanism 56, a pressure reducing mechanism 57, and refrigerant piping 58. In the adjustment unit 12, when the first heat exchanger 51 functions as a condenser (i.e., when the first heat exchanger 51 heats the air), the refrigerant discharged from the compressor 55 flows in the order of the switching mechanism 56, the first heat exchanger 51, the pressure reducing mechanism 57, the second heat exchanger 52, and the switching mechanism 56 before returning to the compressor 55. Each of the parts 51, 52, 55-57 are connected by the refrigerant piping 58.

[0047] The first heat exchanger 51 and the second heat exchanger 52 are, for example, cross-fin type fin-and-tube heat exchangers. Adsorbent 53 is provided on the surface of each fin of the first heat exchanger 51, and adsorbent 54 is provided on the surface of each fin of the second heat exchanger 52.

[0048] The adsorbents 53 and 54 adsorb water vapor from the air. The adsorbents 53 and 54 may be, for example, zeolite, silica gel, or activated carbon, or they may be organic polymer materials having hydrophilic functional groups.

[0049] The compressor 55 is a variable-capacity compressor whose rotation frequency is inverter-controlled based on the operation command of the control unit 17. The switching mechanism 56 is a mechanism for switching the direction of refrigerant flow in the refrigerant piping 58, and is, for example, a four-way switching valve. The switching mechanism 56 is connected to the refrigerant piping 58 by four ports P1 to P4. Port P1 is connected to the discharge side of the compressor 55, and port P2 is connected to the suction side of the compressor 55. Port P3 is connected to the first end side of the first heat exchanger 51, and port P4 is connected to the first end side of the second heat exchanger 52.

[0050] The switching mechanism 56 is switched between a first connection state (shown in Figure 5) and a second connection state (shown in Figure 6) based on a control command from the control unit 17. In the first connection state, ports P1 and P3 are connected, and ports P2 and P4 are connected. In this state, the refrigerant discharged from the compressor 55 is sent to the first heat exchanger 51. In the second connection state, ports P1 and P4 are connected, and ports P2 and P3 are connected. In this state, the refrigerant discharged from the compressor 55 is sent to the second heat exchanger 52.

[0051] The pressure reducing mechanism 57 is a mechanism connected to the second end (opposite the first end) of the first heat exchanger 51 and the second heat exchanger 52, and is, for example, an expansion valve. Based on the control command of the control unit 17, the opening degree of the pressure reducing mechanism 57 is controlled, thereby reducing the pressure of the refrigerant flowing through the pressure reducing mechanism 57.

[0052] [Configuration of detection units 61-66] Detection units 61 to 66 are sensors that detect the temperature, humidity, or pressure of each part of the ventilation device 10, respectively. Detection units 61 to 66 are electrically connected to the control unit 17, and each outputs its detection result to the control unit 17.

[0053] Refer to Figure 1. The first detection unit 61 detects the temperature of the air in the first air supply passage 31a (i.e., the air supply passage 31 on the side of the outdoor space SP1 that is closer to the adjustment unit 12). The first detection unit 61 is, for example, a resistive sensor (thermistor). The first detection unit 61 is, for example, located near the outside air intake 21 and detects the temperature of the outside air (outdoor temperature) taken in from the outside air intake 21.

[0054] The second detection unit 62 detects the humidity of the air in the first air supply passage 31a. The second detection unit 62 may be, for example, a resistive sensor or a capacitive sensor. The second detection unit 62 may be, for example, located near the outside air intake 21 and detect the humidity of the outside air taken in from the outside air intake 21 (outdoor humidity). The second detection unit 62 may be a temperature and humidity sensor integrated with the first detection unit 61.

[0055] Refer to Figure 2. The third detection unit 63 detects the temperature of the air in the first exhaust passage 32a (i.e., the part of the exhaust passage 32 closer to the indoor space SP2 than the adjustment unit 12). The third detection unit 63 is, for example, a resistive sensor. The third detection unit 63 is, for example, located near the return air intake 23 and detects the temperature of the return air (indoor temperature) taken in from the return air intake 23.

[0056] The fourth detection unit 64 detects the humidity of the air in the first exhaust passage 32a. The fourth detection unit 64 may be, for example, a resistive sensor or a capacitive sensor. The fourth detection unit 64 is, for example, located near the return air intake 23 and detects the humidity (room humidity) of the return air taken in from the return air intake 23. The fourth detection unit 64 may be a temperature and humidity sensor integrated with the third detection unit 63.

[0057] Refer to Figure 5. The fifth detection unit 65 and the sixth detection unit 66 are sensors that detect the pressure of the refrigerant flowing through the refrigerant piping 58. The fifth detection unit 65 is installed on the discharge side of the compressor 55 and detects the high-pressure refrigerant pressure. The sixth detection unit 66 is installed on the suction side of the compressor 55 and detects the low-pressure refrigerant pressure. Note that the fifth detection unit 65 and the sixth detection unit 66 only need to be able to detect the condensation pressure and evaporation pressure of the refrigerant in the refrigerant piping 58, and their installation locations are not limited to the example in Figure 5. For example, the fifth detection unit 65 may be installed in the first heat exchanger 51, and the sixth detection unit 66 may be installed in the second heat exchanger 52.

[0058] [Operation of ventilation device 10] The ventilation device 10 selectively performs humidification, dehumidification, simple ventilation, and drying operations according to control commands from the control unit 17. Humidification operation is performed by exhausting the air from the indoor space SP2 while supplying humidified outside air to the indoor space SP2. Dehumidification operation is performed by exhausting the air from the indoor space SP2 while supplying dehumidified outside air to the indoor space SP2. Simple ventilation operation is performed by exhausting the air from the indoor space SP2 while supplying outside air to the indoor space SP2 without performing either dehumidification or humidification. Drying operation is performed to suppress or eliminate condensation on the first opening / closing mechanism 15.

[0059] The control unit 17 switches between humidification, dehumidification, and simple ventilation operation based on input from, for example, a remote controller (remote control) not shown in the figure. For example, if the user instructs the remote control to perform dehumidification, the control unit 17 will perform dehumidification. Also, for example, if the user instructs the remote control to perform automatic operation, the control unit 17 will appropriately perform humidification, dehumidification, and simple ventilation operation based on the indoor temperature detected by the third detection unit 63 and the indoor humidity detected by the fourth detection unit 64.

[0060] [Humidification operation] During humidification operation, the control unit 17 closes the first opening / closing mechanism 15. Also during humidification operation, the control unit 17 alternately repeats the first operation and the second operation, described later, at predetermined time intervals (for example, every 3 minutes). This time interval is also referred to as the "batch time" during humidification operation.

[0061] Figure 5 schematically shows the first operation, and Figure 6 schematically shows the second operation. In Figures 5 and 6, moisture-rich air is indicated by hatched arrows, and moisture-free (dry) air is indicated by white arrows.

[0062] Refer to Figure 5. The first operation of the humidification operation is to pass outside air through the first heat exchanger 51, which functions as a condenser, and to generate humidified supply air by supplying moisture to the outside air from the adsorbent 53, and to generate dehumidified exhaust air by passing return air through the second heat exchanger 52, which functions as an evaporator, and adsorbing the moisture of the return air onto the adsorbent 54. In the first operation, the moisture content of the adsorbent 53 decreases, and the moisture content of the adsorbent 54 increases. Then, after executing the first operation for a batch time, the control unit 17 switches from the first operation to the second operation.

[0063] Specifically, in the first operation, the control unit 17 rotates the compressor 55 by setting the switching mechanism 56 to the first connection state. As a result, the first heat exchanger 51 functions as a condenser and the second heat exchanger 52 functions as an evaporator.

[0064] In the first operation, the control unit 17 opens dampers 41 and 43 and closes dampers 42 and 44, thereby rotating the supply air fan 13. As a result, outside air taken in from the outside air intake 21 into the first supply air passage 31a passes through the first heat exchanger 51 and the second supply air passage 31b, and is blown out from the supply air outlet 22. At this time, moisture is released into the outside air from the adsorbent 53 heated by the first heat exchanger 51, so that the outside air is supplied to the indoor space SP2 as humid supply air.

[0065] In the first operation, the control unit 17 opens dampers 46 and 48 and closes dampers 45 and 47, and rotates the exhaust fan 14. As a result, the return air taken in from the return air intake 23 into the first exhaust passage 32a passes through the second heat exchanger 52 and the second exhaust passage 32b and is blown out from the exhaust outlet 24. At this time, moisture in the return air is adsorbed by the adsorbent 54 cooled by the second heat exchanger 52, and the return air is discharged into the outdoor space SP1 as dry exhaust.

[0066] Refer to Figure 6. The second operation of the humidification operation involves passing outside air through the second heat exchanger 52, which functions as a condenser, and supplying moisture to the outside air from the adsorbent 54 to generate moisture-rich supply air, while simultaneously passing return air through the first heat exchanger 51, which functions as an evaporator, and adsorbing the moisture from the return air onto the adsorbent 53 to generate dry exhaust air.

[0067] Specifically, in the second operation, the control unit 17 sets the switching mechanism 56 to the second connection state and rotates the compressor 55. As a result, the first heat exchanger 51 functions as an evaporator and the second heat exchanger 52 functions as a condenser.

[0068] In the second operation, the control unit 17 closes dampers 41 and 43 and opens dampers 42 and 44, thereby rotating the supply air fan 13. As a result, outside air taken in from the outside air intake 21 into the first supply air passage 31a passes through the second heat exchanger 52 and the second supply air passage 31b, and is blown out from the supply air outlet 22. At this time, moisture is released into the outside air from the adsorbent 54 heated by the second heat exchanger 52, so that the outside air is supplied to the indoor space SP2 as humid supply air.

[0069] In the second operation, the control unit 17 closes dampers 46 and 48 and opens dampers 45 and 47, and rotates the exhaust fan 14. As a result, the return air taken in from the return air intake 23 into the first exhaust passage 32a passes through the first heat exchanger 51 and the second exhaust passage 32b and is blown out from the exhaust outlet 24. At this time, moisture in the return air is adsorbed by the adsorbent 53 cooled by the first heat exchanger 51, and the return air is discharged into the outdoor space SP1 as dry exhaust.

[0070] In the second operation, the moisture content of adsorbent 53 increases, and the moisture content of adsorbent 54 decreases. Then, after executing the second operation for a batch time, the control unit 17 switches the second operation back to the first operation. As described above, by repeating the first and second operations, moisture contained in the return air is supplied to the outside air via adsorbents 53 and 54, thereby humidifying the indoor space SP2.

[0071] [Dehumidification operation] During dehumidification operation, the control unit 17 closes the first opening / closing mechanism 15. Also during dehumidification operation, the control unit 17 alternately repeats the first operation and the second operation, described later, at predetermined time intervals (for example, every 3 minutes). This time interval is also referred to as the "batch time" during dehumidification operation.

[0072] Refer to Figure 5. The first operation of the dehumidification operation is to pass return air through the first heat exchanger 51, which functions as a condenser, and to generate humidified exhaust air by supplying moisture to the return air from the adsorbent 53, and to generate dehumidified supply air by passing outside air through the second heat exchanger 52, which functions as an evaporator, and to adsorb moisture from the outside air onto the adsorbent 54. In the first operation, the moisture content of the adsorbent 53 decreases, and the moisture content of the adsorbent 54 increases. Then, after executing the first operation for a batch time, the control unit 17 switches from the first operation to the second operation.

[0073] Specifically, in the first operation, the control unit 17 rotates the compressor 55 by setting the switching mechanism 56 to the first connection state. As a result, the first heat exchanger 51 functions as a condenser and the second heat exchanger 52 functions as an evaporator.

[0074] In the first operation, the control unit 17 closes dampers 41 and 43 and opens dampers 42 and 44, thereby rotating the supply air fan 13. As a result, outside air taken in from the outside air intake 21 into the first supply air passage 31a passes through the second heat exchanger 52 and the second supply air passage 31b, and is blown out from the supply air outlet 22. At this time, the adsorbent 54 cooled by the second heat exchanger 52 adsorbs moisture from the outside air, so that the outside air is supplied to the indoor space SP2 as dry supply air.

[0075] In the first operation, the control unit 17 closes dampers 46 and 48 and opens dampers 45 and 47, and rotates the exhaust fan 14. As a result, the return air taken in from the return air intake 23 into the first exhaust passage 32a passes through the first heat exchanger 51 and the second exhaust passage 32b and is blown out from the exhaust outlet 24. At this time, moisture is released into the return air from the adsorbent 53 heated by the first heat exchanger 51, so the return air is discharged into the outdoor space SP1 as humid exhaust.

[0076] Refer to Figure 6. The second operation of the dehumidification process involves passing return air through the second heat exchanger 52, which functions as a condenser, and supplying moisture to the return air from the adsorbent 54 to generate humidified exhaust air. At the same time, outside air is passed through the first heat exchanger 51, which functions as an evaporator, and the adsorbent 53 adsorbs moisture from the outside air to generate dehumidified supply air.

[0077] Specifically, in the second operation, the control unit 17 sets the switching mechanism 56 to the second connection state and rotates the compressor 55. As a result, the first heat exchanger 51 functions as an evaporator and the second heat exchanger 52 functions as a condenser.

[0078] In the second operation, the control unit 17 opens dampers 41 and 43 and closes dampers 42 and 44, thereby rotating the supply air fan 13. As a result, outside air taken in from the outside air intake 21 into the first supply air passage 31a passes through the first heat exchanger 51 and the second supply air passage 31b, and is blown out from the supply air outlet 22. At this time, the adsorbent 53 cooled by the first heat exchanger 51 adsorbs moisture from the outside air, so that the outside air is supplied to the indoor space SP2 as dehumidified supply air.

[0079] In the second operation, the control unit 17 opens dampers 46 and 48 and closes dampers 45 and 47, and rotates the exhaust fan 14. As a result, the return air taken in from the return air intake 23 into the first exhaust passage 32a passes through the second heat exchanger 52 and the second exhaust passage 32b and is blown out from the exhaust outlet 24. At this time, moisture is released into the return air from the adsorbent 54 heated by the second heat exchanger 52, so the return air is discharged into the outdoor space SP1 as humid exhaust.

[0080] In the second operation, the moisture content of adsorbent 53 increases, and the moisture content of adsorbent 54 decreases. Then, after executing the second operation for a batch time, the control unit 17 switches the second operation back to the first operation. As described above, by repeating the first and second operations, moisture contained in the outside air is supplied to the return air via adsorbents 53 and 54, thereby dehumidifying the indoor space SP2.

[0081] [Simple ventilation operation] In simple ventilation operation, the control unit 17 opens the first opening / closing mechanism 15, closes dampers 41-44, and opens dampers 45-48, thereby stopping the rotation of the compressor 55. In this state, the control unit 17 rotates the supply fan 13 and the exhaust fan 14.

[0082] As a result, the outside air taken in from the outside air intake 21 into the first supply air passage 31a passes through the first opening 25, the bypass passage 33, the second opening 26, and the second supply air passage 31b in that order, and is blown out from the supply air outlet 22. At this time, the outside air does not pass through either the first heat exchanger 51 or the second heat exchanger 52, so the outside air is supplied directly to the indoor space SP2 as supply air without being humidified or dehumidified by the adjustment unit 12.

[0083] Furthermore, the return air taken in from the return air intake 23 into the first exhaust passage 32a passes through the first heat exchanger 51 or the second heat exchanger 52 in parallel, reaches the second exhaust passage 32b, and is blown out from the exhaust outlet 24. At this time, the compressor 55 is stopped, and neither the first heat exchanger 51 nor the second heat exchanger 52 is heated or cooled, so the return air is discharged as exhaust into the outdoor space SP1 without being humidified or dehumidified by the adjustment unit 12.

[0084] [Regarding condensation in the first opening / closing mechanism 15] As described above, during dehumidification operation, the first opening / closing mechanism 15 is in a closed state. In this state, the outdoor side of the bypass passage 33 is in communication with the first supply air passage 31a through the first opening 25, and therefore the temperature and humidity are approximately equal to the outdoor temperature and humidity. For example, in the summer in Japan, the air on the outdoor side of the first opening / closing mechanism 15 is hot (e.g., 35°C or higher) and humid (e.g., 70% or higher).

[0085] On the other hand, the indoor side of the bypass passage 33 is in communication with the second supply air passage 31b through the second opening 26, so the temperature and humidity are approximately the same as those of the second supply air passage 31b. For example, when the ventilation device 10 is performing dehumidification, the supply air cooled and dehumidified by the first heat exchanger 51 or the second heat exchanger 52 is supplied to the indoor space SP2 via the second supply air passage 31b, so the indoor air on the first opening / closing mechanism 15 is at a low temperature (for example, 30°C or lower).

[0086] In this case, if the first opening / closing mechanism 15, which is in a closed state, is cooled by the indoor air, condensation may form on the first surface 15a (i.e., the high-temperature surface) of the first opening / closing mechanism 15 on the outdoor side. If condensation occurs in the first opening / closing mechanism 15, various problems may occur, such as contamination (rust, water stains, etc.) inside the casing 11 due to water droplets, or short circuits in electrical components.

[0087] Therefore, the control unit 17 determines whether the surface temperature T1 on the first surface 15a of the first opening / closing mechanism 15 is below the dew point temperature T2. If the surface temperature T1 is below the dew point temperature T2, there is a high risk of condensation occurring on the first surface 15a. Therefore, the control unit 17 suppresses unnecessary drying operations by performing a drying operation to dry the first surface 15a only in such cases.

[0088] [Drying operation] Figures 7 and 8 are explanatory diagrams showing the airflow during drying operation. Figure 7 shows the airflow in the internal configuration (lower configuration) of the ventilation device 10 shown in Figure 1, and Figure 8 shows the airflow in the internal configuration (upper configuration) of the ventilation device 10 shown in Figure 2. In Figures 7 and 8, dampers 43, 44, and 48, which are considered to be in the closed state among dampers 41 to 48, are marked with cross-hatching.

[0089] During the drying operation, the control unit 17 opens the first opening / closing mechanism 15, closes the dampers 43, 44, and 48, and opens the dampers 41, 42, 45-47, thereby stopping the rotation of the compressor 55. In this state, the control unit 17 rotates the intake fan 13 and the exhaust fan 14.

[0090] As a result, as shown in the airflow diagram FL1, the outside air taken in from the outside air intake 21 into the first supply air passage 31a passes through the first opening 25, the bypass passage 33, the second opening 26, and the second supply air passage 31b in that order, and is blown out from the supply air outlet 22. At this time, the outside air does not pass through either the first heat exchanger 51 or the second heat exchanger 52, so the outside air is supplied directly to the indoor space SP2 as supply air without being humidified or dehumidified by the adjustment unit 12.

[0091] As shown in Figure 8, the return air taken in from the return air intake 23 into the first exhaust passage 32a is divided into two flows: one that enters the first heat exchanger 51 via the damper 45, and another that enters the second heat exchanger 52 via the damper 46, as shown by airflow FL2. The airflow that enters the first heat exchanger 51 is then blown out from the exhaust outlet 24 via the damper 47, as shown by airflow FL3.

[0092] In the humidification and dehumidification operations described above, dampers 41 to 48 block the supply air passage 31 and the exhaust air passage 32. That is, when damper 41 is in the open state, damper 45, located above damper 41, is in the closed state. Similarly, when dampers 42 to 44 are in the open state, dampers 46 to 48, which are adjacent to these dampers 42 to 44 in the vertical direction, are closed. This prevents the supply air passage 31 and the exhaust air passage 32 from communicating with each other by vertically adjacent dampers during humidification and dehumidification operations.

[0093] On the other hand, during drying operation, the supply air passage 31 and the exhaust air passage 32 are connected by opening both of a pair of dampers adjacent to each other in the vertical direction. Specifically, damper 41 and damper 45 located above damper 41 are opened. Also, damper 42 and damper 46 located above damper 42 are opened. As a result, as shown in the airflow FL4 in Figure 7, a portion of the airflow entering the adjustment unit 12 from damper 45 flows through damper 41 into the first supply air passage 31a, and the airflow entering the adjustment unit 12 from damper 46 flows through damper 42 into the first supply air passage 31a. The airflow FL4 (return air) that flows into the first supply air passage 31a from dampers 41 and 42 flows into the bypass passage 33 together with the airflow FL1 (outside air).

[0094] In this way, the control unit 17 controls the second opening / closing mechanism 16 to connect the supply air passage 31 and the exhaust air passage 32, thereby allowing not only outside air but also return air to flow through the bypass passage 33. The first surface 15a of the first opening / closing mechanism 15 is dried by the outside air and return air. In particular, since the drying operation is performed after the dehumidification operation, the return air is air that has been dehumidified by the dehumidification operation. As a result, the first surface 15a can be dried more quickly by the dehumidified return air, and the drying time required for the drying operation can be shortened.

[0095] The drying operation may be the same as the simple ventilation operation described above. In this case, the first surface 15a is dried by the outside air.

[0096] [Control Method] Figure 9 is a flowchart showing the procedure of the control method according to the embodiment. The control unit 17 determines the timing for executing the drying operation by performing the following control method during the execution of the dehumidification operation. First, the control unit 17 obtains the surface temperature T1 on the first surface 15a of the first opening / closing mechanism 15 (step S11).

[0097] Figure 10 shows a subroutine representing the surface temperature acquisition process S11. In the subroutine, the control unit 17 acquires the intake temperature Toa of the air supplied from the outdoor space SP1 to the air supply passage 31 (step S21). The intake temperature Toa is, for example, the temperature of the outside air (outdoor temperature). The control unit 17 acquires the temperature detected by the first detection unit 61 as the intake temperature Toa. In step S21, the control unit 17 may further acquire various values ​​to be used as variables in equation (1) described later. For example, in addition to the intake temperature Toa, the control unit 17 may acquire values ​​to be used as variables X2 to X9 described later.

[0098] Next, the control unit 17 obtains the outlet temperature Tsa of the air supplied from the air supply passage 31 to the indoor space SP2 (step S22). The outlet temperature Tsa is, for example, the temperature of the supply air. The control unit 17 calculates the outlet temperature Tsa based on the intake temperature Toa.

[0099] The discharge temperature Tsa can be predicted by the intake temperature Toa and the dehumidification capacity of the ventilation device 10. Specifically, the discharge temperature Tsa is predicted by the regression equation shown in equation (1) below.

[0100]

number

[0101] Here, for example, n=9. The coefficients α1~α9,β1 are values ​​obtained by the test. Variable X1 is the intake temperature Toa, variable X2 is the intake humidity Hoa (e.g., outside air humidity, detected by the second detection unit 62), variable X3 is the room temperature Tra (e.g., return air temperature, detected by the third detection unit 63), variable X4 is the room humidity Hra (e.g., return air humidity, detected by the fourth detection unit 64), variable X5 is the rotational speed of the compressor 55, variable X6 is the rotational speed of the supply air fan 13, variable X7 is the rotational speed of the exhaust fan 14, variable X8 is the condensation pressure (e.g., the pressure detected by the fifth detection unit 65), and variable X9 is the evaporation pressure (e.g., the pressure detected by the sixth detection unit 66).

[0102] The control unit 17 may, instead of using equation (1), obtain the temperature detected by a detection unit (not shown) installed near the air supply outlet 22 as the discharge temperature Tsa. However, the temperature of the air supply outlet 22 is unstable and non-uniform depending on the location, compared to, for example, the temperature of the return air intake 23, so there is a risk that the detected temperature will vary depending on where the detection unit is installed.

[0103] In contrast, when predicting the discharge temperature Tsa using equation (1), the discharge temperature Tsa is predicted based on the temperature and humidity of the outside air intake 21 (variables X1, X2), the temperature and humidity of the return air intake 23 (variables X3, X4), various rotational speeds (variables X5~X7), and various pressures (variables X8, X9). Since these variables X1~X9 are obtained as values ​​with relatively little variation, a temperature with less variation can be obtained compared to when the detection unit is installed near the supply air outlet 22. Furthermore, since it is not necessary to install the detection unit near the supply air outlet 22 when predicting the discharge temperature Tsa using equation (1), the cost of installing the detection unit can be reduced.

[0104] Steps S21 and S22 may be performed in any order. After steps S21 and S22, the control unit 17 calculates the surface temperature T1 of the first surface 15a using a known heat transfer calculation (step S23). For example, the control unit 17 calculates the surface temperature T1 based on the intake temperature Toa obtained in step S21, the discharge temperature Tsa obtained in step S22, and the heat transfer coefficient K1 of the first switching mechanism 15. The surface temperature T1 of the first surface 15a is expressed by, for example, the following equation (2).

[0105] T1=Toa-K1·A1(Toa-Tsa) / h1···(2)

[0106] Here, A1 is the heat transfer area of ​​the first surface 15a, and h1 is the heat transfer coefficient between the first surface 15a and the outdoor air. Memory 17b stores, for example, the heat transfer coefficient K1, the heat transfer area A1, and the heat transfer coefficient h1 as parameters. Control unit 17 calculates the surface temperature T1 by substituting the intake temperature Toa and the discharge temperature Tsa into equation (2).

[0107] Note that equation (2) above is an example of a heat transfer calculation, and the control unit 17 may calculate the surface temperature T1 using other known heat transfer calculations. Also, for the sake of simplicity of calculation, the control unit 17 may directly obtain the outlet temperature Tsa as the surface temperature T1. In this case, step S23 can be omitted. With this, step S11 is completed.

[0108] Next, the control unit 17 obtains the dew point temperature T2 of the air adjacent to the first surface 15a (step S12). Here, since the bypass passage 33 is in communication with the first supply air passage 31a via the first opening 25, the temperature and humidity of the air adjacent to the first surface 15a (i.e., the air that causes condensation on the first surface 15a) is approximately equal to the temperature and humidity of the air flowing through the first supply air passage 31a. For this reason, the control unit 17 obtains the dew point temperature Tx of the first supply air passage 31a, which is obtained based on the temperature detected by the first detection unit 61 (temperature of the first supply air passage 31a) and the humidity detected by the second detection unit 62 (humidity of the first supply air passage 31a), as the dew point temperature T2.

[0109] The control unit 17 may also obtain a value as the dew point temperature T2 by adding a predetermined margin value M1 to the dew point temperature Tx (T2 = Tx + M1). For example, if condensation is likely to occur on the first surface 15a, or if the risk of condensation is high and it is desired to perform a drying operation without fail if condensation occurs, the margin value M1 is set to a positive value. On the other hand, if condensation is unlikely to occur on the first surface 15a, or if the risk of condensation is low and it is desired to make it difficult to perform a drying operation, the margin value M1 is set to a negative value.

[0110] Steps S11 and S12 may be performed in any order. After steps S11 and S12, the control unit 17 monitors whether the surface temperature T1 is below the dew point temperature T2 (step S13). If the surface temperature T1 is greater than or equal to the dew point temperature T2 (T1 ≥ T2, NO in step S13), the control unit 17 returns to step S11, for example, after a predetermined waiting time, and then sequentially re-executes steps S11, S12, and S13.

[0111] When the surface temperature T1 is lower than the dew point temperature T2 (T1 < T2, YES in step S13), the control unit 17 accumulates the time during which the dehumidification operation is being performed while the surface temperature T1 is lower than the dew point temperature T2 (step S14).

[0112] Subsequently, the control unit 17 monitors whether or not the integrated time Z1 integrated in step S14 is equal to or greater than a predetermined time Z2 (step S15). The predetermined time Z2 is, for example, 12 hours. When the integrated time Z1 is less than the predetermined time Z2 (Z1 < Z2, NO in step S15), the control unit 17 returns to step S11 after a predetermined waiting time, for example.

[0113] When the integrated time Z1 is equal to or greater than the predetermined time Z2 (Z1 ≥ Z2, YES in step S15), the control unit 17 forcibly stops the dehumidification operation and performs the drying operation for a predetermined drying time (for example, 1 hour) (step S16). After executing the drying operation, the control unit 17 resumes the dehumidification operation and resets the integrated time Z1 (Z1 = 0, step S17).

[0114] As described above, the control unit 17 accumulates the operation time (increases the integrated time Z1) only when the surface temperature T1 is lower than the dew point temperature T2 (that is, when there is a risk of condensation). Then, when the integrated time Z1 becomes equal to or greater than the predetermined time Z2, the drying operation is executed. That is, when there is no risk of condensation even during the dehumidification operation, the integrated time Z1 does not increase, so the drying operation is not executed. Thereby, since the control unit 17 executes the drying operation according to the actual condensation risk, unnecessary drying operations can be suppressed.

[0115] [Modified Example] The present disclosure is not limited to the above-described embodiments, and various modifications are possible. In the following modified examples, the same components as those in the above-described embodiments are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0116] [Modified Example of Surface Temperature Acquisition Step] FIG. 11 is a plan view schematically showing the first opening / closing mechanism 15 according to the modified example and its surroundings. The detection unit 67 is a sensor provided on the first surface 15a (or in the vicinity thereof) of the first opening / closing mechanism 15, which detects the surface temperature T1 and outputs the detection result to the control unit 17. In the surface temperature acquisition step (step S11) according to the embodiment, the surface temperature T1 is calculated through heat transfer calculation in steps S21 to S23. In contrast, the control unit 17 of this modification may acquire the surface temperature T1 actually measured by the detection unit 67.

[0117] [Variant of Step S13] The control unit 17 of the above embodiment executes the drying operation when the surface temperature T1 of the first surface 15a is lower than the dew point temperature T2 (T1 < T2). The surface temperature T1 is calculated, for example, by heat transfer calculation based on the blowing temperature Tsa. However, if the blowing temperature Tsa can be obtained, the surface temperature T1 can be simply obtained by adding or subtracting a predetermined value from the blowing temperature Tsa (for example, T1 ≈ Tsa + γ1). Therefore, the control unit 17 may determine whether to execute the drying operation based on the comparison between the blowing temperature Tsa and the dew point temperature T2 instead of calculating the surface temperature T1.

[0118] Specifically, based on (T1 < T2) and (T1 ≈ Tsa + γ1), the following formula (3) can be approximately derived.

[0119] <照れ γ1 < T2 - Tsa ···(3)

[0120] As shown in formula (3), in step S13, the control unit 17 according to the modification may determine whether the temperature Tsa of the air adjacent to the second surface 15b on the opposite side of the first surface 15a of the first opening / closing mechanism 15 (that is, the blowing temperature Tsa) is lower than the dew point temperature T2 by more than a predetermined threshold value γ1. That is, when the temperature Tsa is lower than the dew point temperature T2, the control unit 17 may determine whether the difference (T2 - Tsa) between the dew point temperature T2 and the temperature Tsa exceeds the threshold value γ1.

[0121] If the result of the determination is that formula (3) is true, the control unit 17 proceeds to step S14, and if formula (3) is false, it returns to step S11 (FIG. 9).

[0122] Thus, when the control unit 17 determines that the conditions under which dew condensation can occur on the first surface 15a (hereinafter referred to as "the first condition") are satisfied, the control unit 17 executes the drying operation. In the above-described embodiment, the first condition is that the surface temperature T1 on the first surface 15a is lower than the dew point temperature T2 of the air adjacent to the first surface 15a (T1 < T2). Also, in this modified example, the first condition is that the temperature Tsa of the air adjacent to the second surface 15b on the opposite side of the first surface 15a of the first opening / closing mechanism 15 is lower than the dew point temperature T2 of the air adjacent to the first surface 15a by more than a predetermined threshold value γ1 (γ1 < T2 - Tsa).

[0123] Rather than using, as in the prior art, the continuous execution of the dehumidifying operation or the humidifying operation for a certain period of time as a trigger for the drying operation, the control unit 17 determines whether dew condensation can actually occur on the first surface 15a, and executes the drying operation when dew condensation can occur on the first surface 15a. Therefore, unnecessary drying operations can be suppressed.

[0124] [Modified Example of Dew Point Temperature Acquisition Step] Referring to FIG. 11, the detection unit 68 is provided on the first opening 25 side (outdoor side) of the first opening / closing mechanism 15 in the bypass passage 33, and is a temperature and humidity sensor that detects the temperature and humidity in the bypass passage 33 and outputs the detection results to the control unit 17. In the dew point temperature acquisition step (step S12) according to the embodiment, the dew point temperature T2 is calculated based on the temperature and humidity detected by the first detection unit 61 and the second detection unit 62 provided near the outside air intake 21. In contrast, the control unit 17 of this modified example may acquire the dew point temperature T2 based on the temperature and humidity detected by the detection unit 68.

[0125] Since the detection unit 68 is provided in the bypass passage 33, it is closer to the first opening / closing mechanism 15 than the first detection unit 61 and the second detection unit 62. Therefore, the control unit 17 of this modified example can more accurately calculate the dew point temperature T2 of the air adjacent to the first surface 15a of the first opening / closing mechanism 15.

[0126] [Modified Example of Drying Operation] Refer to Figure 11. In the above embodiment, the control unit 17 dries the first surface 15a of the first opening / closing mechanism 15 by flowing outside air and return air through the bypass passage 33. In contrast, in this modified example, the first surface 15a is dried by raising the surface temperature T1 with the heating unit 18.

[0127] The heating unit 18 is, for example, a resistance heater and is built into the first switching mechanism 15. The heating unit 18 may be fixed to the first surface 15a of the first switching mechanism 15. Based on the control command of the control unit 17, the heating unit 18 heats the first surface 15a to a temperature higher than the dew point temperature T2. As a result, the surface temperature T1 exceeds the dew point temperature T2, and the first surface 15a dries.

[0128] As described above, the method for drying the first surface 15a during the drying operation is not particularly limited; for example, hot air may be blown onto the first surface 15a.

[0129] [Variation 1 of the timing of starting the drying operation] In the above embodiment, the control unit 17 executes a drying operation in steps S14 and S15 when the accumulated time Z1, which is the sum of the time the surface temperature T1 is below the dew point temperature T2, is equal to or greater than a predetermined time Z2. However, the control unit 17 may also execute a drying operation based on the elapsed time since the time the surface temperature T1 fell below the dew point temperature T2, without counting the accumulated time Z1.

[0130] For example, in step S13, if the surface temperature T1 falls below the dew point temperature T2 (YES in step S13), the control unit 17 stores the time TM1 when the surface temperature T1 fell below the dew point temperature T2 in the memory 17b instead of step S14 (step S14a). Next, instead of step S15, the control unit 17 waits for a predetermined time Z2 from the time TM1 (step S15a). After step S15a, that is, after the predetermined time Z2 has elapsed from time TM1, the control unit 17 performs the drying operation (step S16).

[0131] By configuring it in this way, the control unit 17 can omit the counting process for the accumulated time Z1, thereby reducing the processing load on the control unit 17.

[0132] [Variation 2 of the timing of starting the drying operation] The control unit 17 according to the above embodiment executes a drying operation based on the accumulated time Z1. However, the timing of the execution of the drying operation is not limited to this, and for example, the control unit 17 may execute a drying operation when the accumulated amount MX1, which is the accumulated amount of condensation Q1 on the first surface 15a, exceeds a predetermined value MX2. The control unit 17 calculates the amount of condensation Q1 based on, for example, the difference D1 between the dew point temperature T2 and the surface temperature T1.

[0133] [Example 1 of drying cycle execution time] In the above embodiment, the control unit 17 uniformly performs a drying operation for a predetermined drying time in step S16, regardless of the condensation status on the first surface 15a. However, the control unit 17 may determine the drying time according to the condensation status on the first surface 15a.

[0134] For example, the larger the difference D1 (D1 = T2 - T1) between the dew point temperature T2 and the surface temperature T1, the greater the amount of condensation Q1 on the first surface 15a, and the longer the time required to dry the first surface 15a. For this reason, the control unit 17 may increase the drying time when the difference D1 is large, and decrease the drying time when the difference D1 is small.

[0135] Figure 12 is a graph showing the relationship between the difference between the dew point temperature T2 and the surface temperature T1 and various values. Figure 12(a) is a graph including curve F1 which represents the relationship between the difference and the amount of condensation on the first surface 15a, and Figure 12(b) is a graph including curve F2 which represents the relationship between the amount of condensation on the first surface 15a and the drying time required to dry the first surface 15a. Curves F1 and F2 are obtained, for example, by testing, and the functions and parameters that represent curves F1 and F2 are stored in memory 17b.

[0136] In step S16, the control unit 17 calculates the difference D1 between the dew point temperature T2 and the surface temperature T1. Then, based on the function and parameters representing curve F1 and the difference D1, the control unit 17 calculates the amount of condensation Q1 as shown in Figure 12(a). Subsequently, based on the function and parameters representing curve F2 and the amount of condensation Q1, the control unit 17 calculates the drying time Y1 as shown in Figure 12(b).

[0137] Based on the above, the control unit 17 determines the drying time Y1 according to the difference D1 indicating the condensation status. In step S16, the control unit 17 executes the drying operation for the calculated drying time Y1. This further reduces unnecessary drying operations.

[0138] [Variation 2 of drying operation time] The control unit 17 may determine the drying time Y1 based on statistical values ​​of the condensation amount Q1. For example, while accumulating the dehumidification operation time in step S14, the control unit 17 calculates statistical values ​​(e.g., mean, median) of the condensation amount Q1 obtained based on the difference D1. The control unit 17 then shortens the drying time Y1 as the statistical value of the condensation amount Q1 decreases.

[0139] [Variation of Ventilation System 1] The ventilation device 10 according to the above embodiment is a heat pump desiccant type ventilation device. However, the ventilation devices according to this disclosure are not limited thereto.

[0140] For example, the adjustment unit 12 may include a desiccant rotor. The desiccant rotor includes a desiccant that adsorbs moisture from the air and releases the adsorbed moisture by heating, a heater that heats a part of the desiccant, a cooling coil that cools another part of the desiccant, and a rotor that rotates the desiccant. The adjustment unit 12 continuously controls humidity by switching between a heated region and a cooled region of the desiccant using the rotor.

[0141] [Variation of Ventilation System 2] Figure 13 is a schematic plan view showing the internal configuration of a modified ventilation device 100. The ventilation system 100 is a ventilation system that can switch between total heat exchange ventilation operation and simple ventilation operation. The ventilation system 100 comprises a casing 110, an adjustment unit 120, a supply fan 130, an exhaust fan 140, two first opening / closing mechanisms 150, and a control unit 170.

[0142] The casing 110 has an outside air intake 210, an air supply outlet 220, a return air intake 230, and an exhaust outlet 240. The casing 110 has an air supply passage 310 that supplies outside air to the indoor space as supply air via an adjustment unit 120, an exhaust passage 320 that discharges return air to the outdoor space as exhaust air via the adjustment unit 120, and two bypass passages 330 that connect the indoor space and the outdoor space without going through the adjustment unit 120.

[0143] The two bypass passages 330 include a first bypass passage 330a that connects the outside air intake 210 and the supply air outlet 220 without going through the adjustment unit 120, and a second bypass passage 330b that connects the return air intake 230 and the exhaust outlet 240 without going through the adjustment unit 120.

[0144] The adjustment unit 120 is installed in the middle of the supply air passage 310 and the exhaust air passage 320, and is a unit that supplies heat recovered from the air flowing through one of the supply air passages 310 and exhaust air passage 320 to the air flowing through the other of the supply air passages 310 and exhaust air passage 320. The adjustment unit 120 is, for example, a right-angle total heat exchanger. The adjustment unit 120 is formed so that the passage through which outside air flows and the passage through which return air flows are right-angled with a partition plate in between. In the adjustment unit 120, the outside air exchanges heat with the return air.

[0145] The air supply fan 130 is located near the air supply outlet 220. The air supply fan 130 is, for example, a sirocco fan and rotates based on control commands from the control unit 170. When the air supply fan 130 rotates, outside air is drawn into the casing 110 from the outside air intake 210 and blown out from the air supply outlet 220 through the air supply passage 310 or the first bypass passage 330a.

[0146] The exhaust fan 140 is located near the exhaust outlet 240. The exhaust fan 140 is, for example, a sirocco fan and rotates based on control commands from the control unit 170. When the exhaust fan 140 rotates, return air is drawn into the casing 110 from the return air intake 230 and blown out from the exhaust outlet 240 through the exhaust passage 320 or the second bypass passage 330b.

[0147] The first opening / closing mechanism 15 is provided in the bypass passage 330 and is a mechanism that opens and closes the bypass passage 330 based on a control command from the control unit 17. The first opening / closing mechanism 15 includes a first damper 150a that opens and closes the first bypass passage 330a and a second damper 150b that opens and closes the second bypass passage 330b.

[0148] Furthermore, the control unit 170 closes the first damper 150a and the second damper 150b and rotates the supply fan 130 and the exhaust fan 140 to perform "total heat exchange ventilation operation," which ventilates the indoor space while the outside air taken in through the supply passage 310 and the return air taken in through the exhaust passage 320 are exchanged for heat in the adjustment unit 120.

[0149] In total heat exchange ventilation operation, for example in summer, high-temperature outside air exchanges heat with return air taken in from the air-conditioned indoor space, and is supplied to the indoor space as cooled supply air. This allows ventilation to be performed while maintaining the temperature of the indoor space.

[0150] On the other hand, during the summer, when the total heat exchange ventilation system is in operation, the surface of the first damper 150a on the outside air intake 210 side (the high-temperature side in summer) is in contact with hot and humid air, while the surface of the first damper 150a on the supply air outlet 220 side is in contact with the cold air of the cooled indoor space. As a result, condensation may form on the surface of the first damper 150a on the outside air intake 210 side.

[0151] Similarly, during winter, when the total heat exchange ventilation system is in operation, the surface of the second damper 150b on the return air intake 230 side (the high-temperature side in winter) is in contact with the hot, humid air of the heated indoor space, while the surface of the second damper 150b on the exhaust outlet 240 side is in contact with the cold air from outside. Therefore, condensation may form on the surface of the second damper 150b on the return air intake 230 side.

[0152] Therefore, the control unit 170 determines whether the surface temperature T1 on the high-temperature side surface of the first opening / closing mechanism 150 is below the dew point temperature T2 of the air adjacent to that surface, and if the surface temperature T1 is below the dew point temperature T2, it performs a drying operation to dry the surface.

[0153] The drying operation in this modified configuration is the same as the normal ventilation operation of the ventilation device 100 (an operation that ventilates the indoor space without heat exchange between the outside air and the return air). The control unit 170 opens the damper that is at risk of condensation among the first damper 150a and the second damper 150b, and closes the other damper, and rotates the supply air fan 130 and the exhaust fan 140. For example, in summer, there is a risk of condensation on the first damper 150a, so the control unit 170 opens the first damper 150a.

[0154] In this case, outside air taken in from the outside air intake 210 passes through the first bypass passage 330a and is blown out from the supply air outlet 220. The first damper 150a is dried by the outside air passing through the first bypass passage 330a.

[0155] Furthermore, the return air taken in from the return air intake 230 passes through the exhaust passage 320 and the adjustment unit 120, and is blown out from the exhaust outlet 240. Although the return air passes through the adjustment unit 120, the outside air does not, so no heat exchange occurs between the return air and the outside air.

[0156] Furthermore, the control unit 170 may open both the first damper 150a and the second damper 150b during drying operation. In this case, outside air dries the first damper 150a through the first bypass passage 330a, and return air dries the second damper 150b through the second bypass passage 330b.

[0157] [Other variations] Furthermore, at least a portion of each of the above embodiments may be combined with each other in any way.

[0158] [Effects of the Embodiment] The effects and benefits of the ventilation device according to the embodiment and modified version will be described.

[0159] (1) The ventilation system of the present disclosure includes supply passages 31, 310 through which air supplied from the outdoor space SP1 to the indoor space SP2 flows, exhaust passages 32, 320 through which air discharged from the indoor space SP2 to the outdoor space SP1 flows, and adjustment units 12 provided in the middle of the supply passages 31, 310 and 32, 320, which supply heat or moisture recovered from the air flowing through one of the supply passages 31, 310 and 32, 320 to the air flowing through the other of the supply passages 31, 310 and 32, 320. The ventilation device 10,100 comprises: 120, bypass passages 33,330 that connect the outdoor space SP1 and the indoor space SP2 without passing through the adjustment section 12,120, first opening / closing mechanisms 15,150 provided in the bypass passages 33,330 for opening and closing the bypass passages 33,330, and control units 17,170 that perform a drying operation to dry the first surface 15a when it is determined that the conditions for condensation to occur on the high-temperature side first surface 15a of the first opening / closing mechanism 15,150 are met.

[0160] The control unit 17 executes a drying operation when it determines that condensation may occur on the first surface 15a. This helps to suppress unnecessary drying operations.

[0161] (2) The first condition includes the surface temperature T1 on the first surface 15a being lower than the dew point temperature T2 of the air adjacent to the first surface 15a.

[0162] When the surface temperature T1 falls below the dew point temperature T2, there is a high risk of condensation occurring on the first surface 15a. Therefore, the control units 17 and 170 can suppress unnecessary drying operations by performing a drying operation to dry the first surface 15a only in such cases.

[0163] (3) The control unit 17 obtains the surface temperature T1 based on the outlet temperature Tsa of the air supplied from the air supply passage 31 to the indoor space SP1.

[0164] By configuring it in this way, the detection unit for detecting the surface temperature T1 can be omitted, thereby reducing the cost of installing the detection unit.

[0165] (4) The control unit 17 executes the drying operation when the cumulative amount MX1, which is calculated by accumulating the amount of condensation Q1 on the first surface 15a based on the difference D1 between the dew point temperature T2 and the surface temperature T1, exceeds a predetermined amount.

[0166] By configuring the system in this way, drying operations can be performed more appropriately according to the condensation conditions, thereby reducing unnecessary drying operations.

[0167] (5) When the surface temperature T1 is below the dew point temperature T2, the control unit 17 shortens the drying time Y1 for performing the drying operation as the difference D1 between the dew point temperature T2 and the surface temperature T1 or the statistical value of the difference D1 is smaller.

[0168] By configuring it in this way, the drying time Y1 can be shortened according to the condensation conditions, thereby suppressing unnecessary drying operations.

[0169] (6) The first condition includes that the temperature Tsa of the air adjacent to the second surface 15b of the first opening / closing mechanism 15,150, which is opposite to the first surface 15a, is below the dew point temperature T2 of the air adjacent to the first surface 15a by a predetermined threshold γ1.

[0170] When the temperature Tsa of the air adjacent to the second surface 15b on the opposite side of the first surface 15a falls below the dew point temperature T2 by a threshold γ1, there is a high risk of condensation occurring on the first surface 15a. For this reason, the control units 17 and 170 can suppress unnecessary drying operations by performing a drying operation to dry the first surface 15a only in such cases.

[0171] (7) The control unit 17 executes the drying operation when the cumulative time Z1 obtained by accumulating the time that satisfies the first condition becomes equal to or greater than a predetermined time Z2.

[0172] As long as the first condition is not met, the cumulative time Z1 does not increase, and therefore the drying operation is not performed. By configuring it in this way, unnecessary drying operations can be further suppressed.

[0173] (8) The control unit 17 executes the drying operation when a predetermined time Z2 has elapsed from the time TM1 at which it determined that the first condition was met.

[0174] By configuring it in this way, the control unit 17 can omit the counting process for the accumulated time Z1, thereby reducing the processing load on the control unit 17.

[0175] (9) The control unit 17 can switch between a first operation in which ventilation is performed via the supply air passage 31 and the exhaust air passage 32, and a second operation in which ventilation is performed via the bypass passage 33, and the drying operation is the second operation.

[0176] This configuration allows the first opening / closing mechanism 15 to be dried in parallel with the ventilation of the indoor space SP2. [Explanation of Symbols]

[0177] 10: Ventilation device, 11: Casing, 11a: First compartment wall, 11b: Second compartment wall, 12: Adjustment unit, 13: Supply fan, 14: Exhaust fan, 15: First opening / closing mechanism, 15a: First surface, 15b: Second surface, 16: Second opening / closing mechanism, 17: Control unit, 17a: Processor, 17b: Memory, 18: Heating unit, 100: Ventilation device, 110: Casing, 120: Adjustment unit, 130: Supply fan, 140: Exhaust fan, 150: First opening / closing mechanism, 150a: First damper, 150b: Second damper, 170: Control unit, 21: Outside 1: Air intake, 22: Air supply outlet, 23: Return air intake, 24: Exhaust outlet, 25: First opening, 26: Second opening, 31: Air supply passage, 31a: First air supply passage, 31b: Second air supply passage, 32: Exhaust passage, 32a: First exhaust passage, 32b: Second exhaust passage, 33: Bypass passage, 310: Air supply passage, 320: Exhaust passage, 330: Bypass passage, 330a: First bypass passage, 330b: Second bypass passage, 41: Damper, 42: Damper, 43: Damper, 44: Damper, 45: Damper, 46: Damper, 47: Damper P1: Damper, 48: Damper, 51: First heat exchanger, 52: Second heat exchanger, 53: Adsorbent, 54: Adsorbent, 55: Compressor, 56: Switching mechanism, 57: Pressure reducing mechanism, 58: Refrigerant piping, 61: First detection unit, 62: Second detection unit, 63: Third detection unit, 64: Fourth detection unit, 65: Fifth detection unit, 66: Sixth detection unit, 67: Detection unit, 68: Detection unit, SP1: Outdoor space, SP2: Indoor space, SP3: Upper space, SP4: Lower space, P1: Port, P2: Port, P3: Port, P4: Port, T1: Surface temperature, T2: Dew point temperature, Toa: Intake temperature, Tsa: Outlet temperature, Tx: Dew point temperature, FL1: Airflow, FL2: Airflow, FL3: Airflow, FL4: Airflow, X1: Variable, X2: Variable, X3: Variable, X4: Variable, X5: Variable, X6: Variable, X7: Variable, X8: Variable, X9: Variable, K1: Heat transfer coefficient, A1: Heat transfer area, h1: Heat transfer coefficient, M1: Margin value, Z1: Cumulative time, Z2: Scheduled time, MX1: Cumulative amount, MX2: Scheduled value, TM1: Time, D1: Difference, Q1: Condensation amount, F1: Curve, F2: Curve, Y1: Drying time, γ1: Threshold

Claims

1. An air supply passage (31, 310) through which air supplied from the outdoor space (SP1) to the indoor space (SP2), An exhaust passage (32, 320) through which air discharged from the indoor space (SP2) to the outdoor space (SP1) flows, An adjustment unit (12, 120) is provided in the middle of the supply air passage (31, 310) and the exhaust air passage (32, 320) and supplies heat or moisture recovered from the air flowing through one of the supply air passage (31, 310) and the exhaust air passage (32, 320) to the air flowing through the other of the supply air passage (31, 310) and the exhaust air passage (32, 320), Bypass passages (33, 330) that connect the outdoor space (SP1) and the indoor space (SP2) without passing through the adjustment sections (12, 120), A first opening / closing mechanism (15, 150) is provided in the bypass passage (33, 330) and opens and closes the bypass passage (33, 330), When it is determined that the first condition, which is the condition under which condensation may occur on the first surface (15a) on the high-temperature side of the first opening / closing mechanism (15, 150), is met, the control unit (17, 170) executes a drying operation to dry the first surface (15a), Equipped with, The first condition includes the surface temperature (T1) of the first surface (15a) being lower than the dew point temperature (T2) of the air adjacent to the first surface (15a), in the ventilation device (10, 100).

2. An air supply passage (31, 310) through which air supplied from the outdoor space (SP1) to the indoor space (SP2) flows, An exhaust passage (32, 320) through which air discharged from the indoor space (SP2) to the outdoor space (SP1) flows, An adjustment unit (12, 120) is provided in the middle of the supply air passage (31, 310) and the exhaust air passage (32, 320) and supplies heat or moisture recovered from the air flowing through one of the supply air passage (31, 310) and the exhaust air passage (32, 320) to the air flowing through the other of the supply air passage (31, 310) and the exhaust air passage (32, 320), Bypass passages (33, 330) that connect the outdoor space (SP1) and the indoor space (SP2) without passing through the adjustment sections (12, 120), A first opening / closing mechanism (15, 150) is provided in the bypass passage (33, 330) and opens and closes the bypass passage (33, 330), When it is determined that the first condition, which is the condition under which condensation may occur on the first surface (15a) on the high-temperature side of the first opening / closing mechanism (15, 150), is met, the control unit (17, 170) executes a drying operation to dry the first surface (15a), Equipped with, The first condition includes the temperature (Tsa) of the air adjacent to the second surface (15b) of the first opening / closing mechanism (15, 150) opposite to the first surface (15a) being lower than the dew point temperature (T2) of the air adjacent to the first surface (15a) by a predetermined threshold (γ1), for a ventilation device (10, 100).

3. An air supply passage (31, 310) through which air supplied from the outdoor space (SP1) to the indoor space (SP2) flows, An exhaust passage (32, 320) through which air discharged from the indoor space (SP2) to the outdoor space (SP1) flows, An adjustment unit (12, 120) is provided in the middle of the supply air passage (31, 310) and the exhaust air passage (32, 320) and supplies heat or moisture recovered from the air flowing through one of the supply air passage (31, 310) and the exhaust air passage (32, 320) to the air flowing through the other of the supply air passage (31, 310) and the exhaust air passage (32, 320), Bypass passages (33, 330) that connect the outdoor space (SP1) and the indoor space (SP2) without passing through the adjustment sections (12, 120), A first opening / closing mechanism (15, 150) is provided in the bypass passage (33, 330) and opens and closes the bypass passage (33, 330), When it is determined that the first condition, which is the condition under which condensation may occur on the first surface (15a) on the high-temperature side of the first opening / closing mechanism (15, 150), is met, the control unit (17, 170) executes a drying operation to dry the first surface (15a), Equipped with, The elements that determine the first condition are, A first element which is one of the following: surface temperature (T1) on the first surface (15a), temperature (Tsa) of the air adjacent to the second surface (15b) on the opposite side of the first surface (15a) of the first opening / closing mechanism (15, 150), and outlet temperature (Tsa) of the air supplied from the air supply passage (31) to the indoor space (SP2), and A ventilation device (10, 100) that includes both a second element which is the dew point temperature (T2) of the air adjacent to the first surface (15a), or the dew point temperature (Tx) of the air supplied from the outdoor space (SP1) to the air supply passage (31).

4. The control unit (17) obtains the surface temperature (T1) based on the outlet temperature (Tsa) of the air supplied from the air supply passage (31) to the indoor space (SP2). The ventilation device (10) according to claim 1.

5. (Old claim 4) The control unit (17) executes the drying operation when the cumulative amount (MX1) obtained by accumulating the amount of condensation (Q1) on the first surface (15a), which is calculated based on the difference (D1) between the dew point temperature (T2) and the surface temperature (T1), exceeds a predetermined amount. A ventilation device (10) according to claim 1 or claim 4.

6. (Old claim 5) The control unit (17) shortens the drying time (Y1) for performing the drying operation when the surface temperature (T1) is below the dew point temperature (T2), and the smaller the difference (D1) between the dew point temperature (T2) and the surface temperature (T1), or the smaller the statistical value of the difference (D1). A ventilation device (10) according to any one of claims 1, 4, and 5.

7. The ventilation device (10) according to any one of claims 1 to 6, wherein the control unit (17) executes the drying operation when the accumulated time (Z1) obtained by accumulating the time that satisfies the first condition becomes equal to or greater than a predetermined time (Z2).

8. The control unit (17) executes the drying operation when a predetermined time (Z2) has elapsed from the time (TM1) at which it determined that the first condition is met. A ventilation device (10) according to any one of claims 1 to 6.

9. The control unit (17) can switch between a first operation, which performs ventilation through the supply air passage (31) and the exhaust air passage (32), and a second operation, which performs ventilation through the bypass passage (33). The drying operation is the second operation. A ventilation device (10) according to any one of claims 1 to 8.

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