Dehumidification system

Abstract

This invention provides a dehumidification system that can stably control the dew point in a low-dew-point room, even when the number of people in the room changes. [Solution] The dehumidification system 1 includes a dehumidifying rotor 101 having a first area provided in a first duct 131 connected to the room 20 that adsorbs moisture contained in mixed air including outside air and discharges dehumidified air to the first duct 131, and a second area provided in a second duct 132 connected to an exhaust port that discharges humid air containing the adsorbed moisture to the second duct 132, a fan 112 provided on the inlet side of the first area that adjusts the airflow rate of the mixed air to increase or decrease the amount of dehumidified air being blown, and a sensor 40 that detects people in the room 20. The dehumidification system 1 estimates the number of people in the room 20 based on the person detection information acquired by the sensor 40. Based on at least the estimated number of people and a second dew point temperature indicating the dew point temperature of the room, the dehumidification system 1 gradually changes at least one of the airflow rate of the fan 112 and the first dew point temperature indicating the dew point temperature of the dehumidified air.

Description

Technical Field

[0001] The present disclosure relates to a dehumidification system that supplies low dew point air into a room.

Background Art

[0002] Patent Document 1 discloses a dew point adjustment method for adjusting the dew point of dry air supplied to a drying device using a dry dehumidifier (dehumidification rotor). The dew point adjustment method uses a dehumidification rotor to adjust the dew point of the circulating air from the drying device to be lower than the steady supply dew point, and humidifies the outlet dew point of the dehumidification rotor with a humidifier on the air supply side of the subsequent stage to adjust it to the steady supply dew point, and supplies the dry air to the drying device. The dew point adjustment method raises the regeneration air temperature passed through the dehumidification rotor by a regeneration air heater (regeneration heater) within a certain time when the drying state becomes a steady state.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, consider the case where the number of people in a low dew point room increases in a short time. In this case, in the dew point adjustment method as shown in Patent Document 1, the outlet dew point of the dehumidification rotor is adjusted regardless of the number of people in the low dew point room, and there is a possibility that the dew point in the low dew point room cannot be appropriately controlled.

[0005] <病気の名称>One object of the present disclosure is to provide a dehumidification system that can stably control the dew point in a low dew point room even when the number of people in the low dew point room changes.

Means for Solving the Problems

[0006] One aspect of this disclosure relates to a dehumidification system for supplying low-dew-point air into a room. The dehumidification system includes a dehumidifying rotor having a first area provided in a first duct connected to the room, which adsorbs moisture contained in a mixed air including outside air and discharges dehumidified air to the first duct, and a second area provided in a second duct connected to an exhaust port, which discharges humid air containing the adsorbed moisture to the second duct; a fan provided on the inlet side of the first area in the first duct, which adjusts the airflow rate of the mixed air to increase or decrease the airflow rate of the dehumidified air; a sensor provided in the room for detecting people in the room; and controllers connected to the sensor and the fan, respectively. The controller estimates the number of people in the room based on person detection information acquired by the sensor. Based on at least the estimated number of people and a second dew-point temperature indicating the dew-point temperature of the room, the controller gradually changes the airflow rate of the fan and at least one of the first dew-point temperature indicating the dew-point temperature of the dehumidified air. [Effects of the Invention]

[0007] According to this disclosure, the number of people in a room is estimated based on person detection information acquired by a sensor. Furthermore, at least one of the fan's airflow and the first dew point temperature is changed in steps based on at least the estimated number of people and the second dew point temperature. This allows for stable control of the dew point in a low-dew-point room, even when the number of people in the room changes. [Brief explanation of the drawing]

[0008] [Figure 1] This is a diagram illustrating an example configuration of a dehumidification system according to Embodiment 1. [Figure 2] This is a block diagram showing an example of the functional configuration of the controller according to Embodiment 1. [Figure 3] This is a diagram illustrating an example of fan airflow setting according to Embodiment 1. [Figure 4] This flowchart shows an example of the processing performed by the controller according to Embodiment 1. [Figure 5] This is a block diagram showing an example of the functional configuration of a controller according to a modified example (first modified example) of Embodiment 1. [Figure 6] This flowchart shows an example of the processing of a controller according to a modified example (first modified example) of Embodiment 1. [Figure 7] This is a block diagram showing an example of the functional configuration of a controller according to a modified example (second modified example) of Embodiment 1. [Figure 8] This flowchart shows an example of the processing of a controller according to a modified example (second modified example) of Embodiment 1. [Figure 9] This figure illustrates a first example of setting the dew point temperature according to a modified example of Embodiment 1. [Figure 10] This is an explanatory diagram showing an example of how the first example of the set dew point temperature changes based on the change in the number of people in the room can be adjusted. [Figure 11] This figure illustrates a second example of setting the dew point temperature according to a modified example of Embodiment 1. [Figure 12] This is an explanatory diagram showing an example of how the setting of the dew point temperature changes based on the change in the number of people in the room. [Figure 13] This figure illustrates an example of fan airflow setting according to a second modified example of Embodiment 1. [Figure 14] This is a diagram illustrating an example of the configuration of a dehumidification system according to Embodiment 2. [Figure 15] This is a block diagram showing an example of the functional configuration of the controller according to Embodiment 2. [Figure 16] This is a diagram illustrating an example of controlling the opening degree of a control valve according to Embodiment 2. [Figure 17] This is a flowchart showing a first processing example of the controller according to Embodiment 2. [Figure 18] This flowchart shows a second processing example of the controller according to Embodiment 2. [Figure 19] This is a diagram illustrating an example configuration of a dehumidification system according to Embodiment 3. [Figure 20] This flowchart shows an example of the processing performed by the controller according to Embodiment 3. [Modes for carrying out the invention]

[0009] Referring to the accompanying drawings, a dehumidification system according to an embodiment of the present disclosure will be described. Also, for elements common to each figure, the same reference numerals are given and duplicate descriptions are omitted.

[0010] 1. Embodiment 1 1-1. Configuration example of the dehumidification system FIG. 1 is a diagram for explaining a configuration example of a dehumidification system 1 according to Embodiment 1. The dehumidification system 1 supplies low dew point air to a low dew point chamber 20 (also simply referred to as an indoor chamber 20). The low dew point chamber 20 is managed, for example, in a dew point temperature range of -50°C DP to -30°C DP. Examples of the low dew point chamber 20 include a dry room, a clean room, and the like.

[0011] The dehumidification system 1 includes a low dew point chamber 20, a dry dehumidifier 100, and a controller 30. The dry dehumidifier 100 generates air to be supplied to the low dew point chamber 20. The dry dehumidifier 100 includes, for example, a first duct 131, a second duct 132, a dehumidification rotor 101, a first fan 112, a second fan 124, a regeneration heater 121, a pre-cooler 111, an after-cooler 114, and an after-heater 115.

[0012] One end of the first duct 131 is connected to an outdoor air inlet, and the other end is connected to the low dew point chamber 20. One end of the second duct 132 is connected to the outdoor air inlet, and the other end is connected to an exhaust port. The outdoor air inlet connected to the first duct 131 and the outdoor air inlet connected to the second duct 132 may be the same or different. Further, a third duct 133 is provided in the dehumidification system 1. The third duct 133 is a pipe for allowing the return air from the low dew point chamber 20 to flow into the dry dehumidifier 100 and exhausting it to the exhaust port. One end of the third duct 133 is connected to the low dew point chamber 20, and the other end is connected to the exhaust port and the first duct 131. The exhaust port connected to the third duct 133 and the exhaust port connected to the second duct 132 may be the same or different.

[0013] The dehumidifying rotor 101 has a rotation mechanism that rotates in one direction and can rotate at any rotational speed. The dehumidifying rotor 101 is equipped with a power converter 102 (also simply called an inverter 102) for driving and controlling the rotation mechanism. The rotation mechanism is driven and controlled based on commands from the inverter 102. The inverter 102 is controlled by the controller 30.

[0014] The dehumidifying rotor 101 has a first area and a second area. The first area has the function of adsorbing moisture contained in the mixed air, which includes outside air drawn in from the outside air inlet via the first filter 110 and return air from the low dew point chamber 20, and discharging dehumidified air. The second area has the function of discharging humid air, which includes the adsorbed moisture and outside air drawn in from the outside air inlet via the second filter 120. The humid air may include the mixed air (outside air and return air) drawn into the first duct 131. For example, if a first branch duct 131A is provided between the inlet side of the first area in the first duct 131 and the inlet side of the second area in the second duct 132, the mixed air drawn into the first duct 131 is supplied to the second duct 132 via the first branch duct 131A.

[0015] The first fan 112 is located in the first duct 131 on the inlet side of the first area of ​​the dehumidifying rotor 101. It draws in outside air from the outside air port and return air from the low dew point chamber 20 to produce a mixed air, which is then sent towards the inlet side of the first area. The mixed air is also sent towards the second duct 132 via the first branch duct 131A. The first fan 112 is equipped with a power converter 113 (also simply referred to as inverter 113) for driving the fan. The inverter 113 is controlled by the controller 30. The first fan 112 is also simply referred to as "fan 112".

[0016] The second fan 124 is located in the second duct 132 on the outlet side of the second area of ​​the dehumidifying rotor 101. It draws in outside air from the outside air port and sends it towards the inlet side of the second area, and exhausts hot, humid air heated by the regenerative heater 121 from the outlet side of the second area and sends it towards the exhaust port. The second fan 124 is equipped with a power converter 125 (also simply called an inverter 125) for driving the fan. The inverter 125 is controlled by the controller 30. The second fan 124 is also called a regenerative fan 124.

[0017] The regeneration heater 121 is installed in the second duct 132 on the inlet side of the second area of ​​the dehumidifying rotor 101 and heats the humid air. The regeneration heater 121 is equipped with a thyristor 122 that adjusts the heater's power. The thyristor 122 is controlled by the controller 30. The temperature of the humid air heated by the regeneration heater 121 is monitored by the controller 30. The temperature of the humid air is measured, for example, by a thermometer 123 (also referred to as thermometer T) installed in the second duct 132 on the inlet side of the second area of ​​the dehumidifying rotor 101.

[0018] The precooler 111 is installed in the first duct 131 between the first filter 110 and the first fan 112. The precooler 111 cools the outside air drawn in from the outside air inlet, or the mixed air containing the outside air from the outside air inlet and the return air from the low dew point chamber 20. In this case, the precooler 111 may be supplied with chilled water to cool the outside air or the mixed air.

[0019] The aftercooler 114 cools the dehumidified air discharged from the dehumidifying rotor 101. This suppresses the temperature rise of the dehumidified air. In this case, the aftercooler 114 may be supplied with chilled water to cool the dehumidified air.

[0020] The afterheater 115 heats the dehumidified air cooled by the aftercooler 114. This further improves the drying effect of the dehumidified air.

[0021] The controller 30 controls the dry dehumidifier 100 to supply low-dew-point air to the low-dew-point chamber 20. Specifically, the controller 30 controls the dehumidifying rotor 101, the regenerating heater 121, the first fan 112, and the second fan 124 based on the second dew-point temperature 22 (also referred to as the second dew-point temperature DP2), which indicates the dew-point temperature of the low-dew-point chamber 20 (indoors), and the first dew-point temperature 11 (also referred to as the first dew-point temperature DP1), which indicates the dew-point temperature of the dehumidified air supplied to the low-dew-point chamber 20.

[0022] Here, we consider the number of people present in the low dew point chamber 20 (occupancy). For example, if the number of occupants increases, the total amount of moisture (humidification) generated from the human body increases, causing the second dew point temperature 22 to rise. On the other hand, if the number of occupants decreases, the total amount of moisture (humidification) generated from the human body decreases, causing the second dew point temperature 22 to fall. For this reason, it is preferable to appropriately adjust the second dew point temperature 22 of the low dew point chamber 20 based on the number of occupants.

[0023] According to this embodiment, the dehumidification system 1 is further equipped with a sensor 40 for detecting people. Examples of the sensor 40 include a motion sensor, a camera, etc. The controller 30 estimates the number of people (occupants) in the low dew point room 20 based on the sensor information obtained from the sensor 40. This makes it possible to determine the number of people in the low dew point room 20. Furthermore, the controller 30 adjusts the airflow rate of the dehumidified air supplied to the low dew point room 20 based on the estimated number of occupants. This makes it possible to suppress fluctuations in the second dew point temperature 22 in the low dew point room 20 even when the number of occupants changes. Therefore, the dew point in the low dew point room 20 can be stably controlled. Details of the various controls performed by the controller 30 will be described later.

[0024] 1-2. Example of Controller Functional Configuration Figure 2 is a block diagram showing an example of the functional configuration of the controller 30 according to Embodiment 1. The controller 30 includes a room occupancy estimation unit 210, an airflow calculation unit 220, and an equipment drive control unit 230.

[0025] The occupancy estimation unit 210 estimates the number of people (occupancy N) in the low dew point room 20 based on the sensor information obtained from the sensor 40. For example, if the sensor 40 is a motion sensor, the occupancy estimation unit 210 estimates the occupancy N based on the person detection information from the motion sensor. For example, if motion sensors are installed both outside and inside the low dew point room 20, and the motion sensors detect a person in the order of the motion sensor installed outside and then the motion sensor installed inside, it is understood that the person has entered the low dew point room 20. In this case, the occupancy estimation unit 210 counts the occupancy N increment by 1. On the other hand, if the motion sensors detect a person in the order of the motion sensor installed inside and then the motion sensor installed outside, it is understood that the person has left the low dew point room 20. In this case, the occupancy estimation unit 210 counts the occupancy N increment by 1. This allows us to estimate the number of people N in the low dew point room 20.

[0026] As another example, if the sensor 40 is a camera, the occupancy estimation unit 210 performs person detection by image processing based on the camera image information acquired by the camera. Then, based on the person detection information, the occupancy estimation unit 210 counts the detected people. This makes it possible to estimate the number of occupants N in the low dew point room 20.

[0027] The airflow calculation unit 220 calculates the amount of dehumidified air Q, which indicates the amount of dehumidified air supplied to the low dew point room 20 according to the number of occupants N obtained by the occupant estimation unit 210, the first dew point temperature 11, and the second dew point temperature 22. Specifically, the amount of dehumidified air Q is expressed, for example, by the following equation (1). Qr is the amount of air supplied to the low dew point room 20, and Qp is a predetermined fixed amount of air supplied. Qr is called the required indoor air supply Qr, and Qp is called the added air supply Qp. The units of Q, Qr, and Qp are all expressed in [m3 / h].

[0028]

number

[0029] The required indoor airflow rate Qr can be expressed, for example, by the following equation (2). S is the amount of moisture released by a person, S0 is the absolute humidity at the air intake (also called the outlet) of the low dew point room 20, and S1 is the absolute humidity inside the low dew point room 20. S is referred to as the amount of moisture released S, S0 as the absolute humidity at the outlet S0, and S1 as the absolute humidity inside the room S1. The unit of the amount of moisture released S is expressed in [g / h], and the units of S0 and S1 are both expressed in [g / kg].

[0030]

number

[0031] Furthermore, the discharge absolute humidity S0 may be calculated based on, for example, the first dew point temperature 11, or based on the number of occupants N and the indoor absolute humidity S1, or it may be a value obtained by a measuring instrument, or it may be a predetermined fixed value. Also, the indoor absolute humidity S1 may be calculated based on, for example, the second dew point temperature 22, or it may be a value obtained by a measuring instrument, or it may be a predetermined fixed value.

[0032] The added airflow rate Qp is expressed, for example, by the following equation (3). Qv is the airflow rate required to maintain the positive pressure in the low dew point chamber 20, and Qe is the exhaust rate locally discharged from the low dew point chamber 20. Qv is referred to as the airflow rate for the positive pressure in the room, and Qe is referred to as the local exhaust rate Qe. The units of Qv and Qe are both expressed in [g / kg].

[0033]

number

[0034] The amount of moisture generated S is expressed, for example, by the following equation (4). Su is the amount of moisture generated per person, N is the number of people in the room N, and So is the amount of moisture generated due to other factors. Both Su and So are expressed in units of [g / h]. The amount of moisture generated per person Su and the amount of other moisture generated So are, for example, predetermined fixed values.

[0035]

number

[0036] The equipment drive control unit 230 performs first fan airflow adjustment control 231 of the first fan 112 based on the amount of dehumidified air Q obtained by the airflow calculation unit 220 and the second dew point temperature 22. Specifically, if the amount of dehumidified air Q is less than the minimum airflow Qmin, that is, if the number of occupants N is less than a predetermined number and does not affect the fluctuation of the second dew point temperature 22, the first fan airflow adjustment control 231 sets the airflow of the first fan 112 to the minimum airflow Qmin, as shown in Figure 3. If the amount of dehumidified air Q is greater than or equal to the minimum airflow Qmin, that is, if the number of occupants N is greater than or equal to a predetermined number and affects the fluctuation of the second dew point temperature 22, the first fan airflow adjustment control 231 changes the airflow of the first fan 112 in steps so that the airflow of the first fan 112 approaches the amount of dehumidified air Q, as shown in Figure 3. By gradually changing the airflow of the first fan 112, even if the number of occupants N fluctuates rapidly, the frequency of switching the airflow of the first fan 112 is reduced, thereby suppressing fluctuations in the second dew point temperature 22 in the low dew point chamber 20. Consequently, the dew point in the low dew point chamber 20 can be stably controlled.

[0037] Here, we consider the first dew point temperature 11 supplied to the low dew point chamber 20 when the airflow rate of the first fan 112 is changed in stages. If the first dew point temperature 11 changes while the control of changing the airflow rate of the first fan 112 in stages is being executed, it becomes impossible to control the airflow rate of the first fan 112 in stages, and the control of the controller 30 may become unstable. For this reason, when changing the airflow rate of the first fan 112 in stages, it is preferable that the first dew point temperature 11 remains constant. According to the controller 30 of Embodiment 1, at least one of the airflow rate of the second fan 124, the temperature of the regenerative heater 121, and the rotation speed of the dehumidifying rotor 101 is adjusted to keep the first dew point temperature 11 constant. This makes it possible to keep the first dew point temperature 11 constant even when changing the airflow rate of the first fan 112 in stages. Furthermore, as a method for keeping the first dew point temperature 11 constant, the controller 30 may set a set dew point temperature SP to bring the first dew point temperature 11 closer to the target dew point temperature. In this case, a fixed value is set as the set dew point temperature SP. This makes it possible to make the first dew point temperature 11 follow the set dew point temperature SP (fixed value), and thus keep the first dew point temperature 11 constant. The fixed value of the set dew point temperature SP is calculated based on at least one of the following: the airflow setting information of the second fan 124, the temperature setting information of the regenerative heater 121, and the rotation speed setting information of the dehumidifying rotor 101.

[0038] The process of gradually changing the airflow of the first fan 112 is repeatedly executed until the second dew point temperature 22 falls below the target dew point temperature (e.g., -30°C DP). When adjusting the airflow of the first fan 112, the equipment drive control unit 230 (first fan airflow adjustment control 231) generates and outputs a drive control signal (e.g., a PWM signal) to the inverter 113 based on the airflow setting information of the first fan 112. When adjusting the airflow of the second fan 124, the equipment drive control unit 230 (second fan airflow adjustment control 232) generates and outputs a drive control signal (e.g., a PWM signal) to the inverter 125 based on the airflow setting information of the second fan 124. When adjusting the temperature of the regenerative heater 121, the equipment drive control unit 230 (regenerative heater temperature adjustment control 233) generates and outputs a control signal to the thyristor 122 based on the temperature setting information of the regenerative heater 121. When adjusting the rotational speed of the dehumidifying rotor 101, the equipment drive control unit 230 (dehumidifying rotor rotation speed control 234) generates and outputs a drive control signal (e.g., a PWM signal) to the inverter 102 based on the rotational speed setting information of the dehumidifying rotor 101.

[0039] Furthermore, if the amount of dehumidified air Q is equal to or greater than the minimum airflow rate Qmin, the airflow rate of the first fan 112 may be changed in stages, for example, each time the number of people N in the room increases or decreases by 3.

[0040] 1-3. Example of controller processing Figure 4 is a flowchart showing an example of processing by the controller 30 according to Embodiment 1.

[0041] In step S100, the dehumidification system 1 (controller 30) calculates the discharge absolute humidity S0 based on the first dew point temperature 11. The process then proceeds to step S120.

[0042] In step S110, the controller 30 estimates the number of people N in the room based on the sensor information obtained from the sensor 40. The process then proceeds to step S120.

[0043] In step S120, the controller 30 calculates the amount of dehumidified air Q to be supplied to the low dew point room 20 based on the number of occupants N and the discharge absolute humidity S0. The process then proceeds to step S130.

[0044] In step S130, the controller 30 determines whether the amount of dehumidified air Q is equal to or greater than the minimum airflow rate Qmin. If it is determined that the amount of dehumidified air Q is equal to or greater than the minimum airflow rate Qmin (step S130; Yes), the process proceeds to step S140. Otherwise (step S130; No), the process proceeds to step S160.

[0045] In step S140, the controller 30 controls various devices based on the amount of dehumidified air Q. Specifically, the controller 30 gradually changes the airflow of the first fan 112. The controller 30 also adjusts at least one of the following: the airflow of the second fan 124, the temperature of the regenerative heater 121, and the rotation speed of the dehumidifying rotor 101, in order to keep the first dew point temperature 11 constant. The process then proceeds to step S150.

[0046] In step S150, the controller 30 determines whether the second dew point temperature 22 is below the target dew point temperature. If it is determined that the second dew point temperature 22 is below the target dew point temperature (step S150; Yes), the process ends. Otherwise (step S150; No), the process returns to step S140. In other words, the process in step S140 is repeatedly executed until the second dew point temperature 22 is below the target dew point temperature.

[0047] In step S160, the controller 30 fixes the airflow of the first fan 112 to the minimum airflow Qmin and outputs it. The process then proceeds to step S150.

[0048] 1-4. Variations In the above-described embodiment 1, the airflow rate of the first fan 112 is changed in stages while keeping the first dew point temperature 11 constant, based on the number of people N in the room. In contrast, in a modified version of embodiment 1, the set dew point temperature SP relative to the first dew point temperature 11 is set in stages, based on the number of people N in the room.

[0049] Let's consider the discharge absolute humidity S0, which indicates the moisture balance. The discharge absolute humidity S0 can be expressed, for example, using equations (1) to (4) described above, as shown in equation (5) below. According to equation (5), the discharge absolute humidity S0 changes in steps based on the number of occupants N. Therefore, if the first dew point temperature 11 is calculated based on the discharge absolute humidity S0, the set dew point temperature SP corresponding to the first dew point temperature 11 will also be set in steps based on the number of occupants N.

[0050]

number

[0051] Here, we consider the airflow of the first fan 112 when the set dew point temperature SP for the first dew point temperature 11 is set in steps, that is, when the first dew point temperature 11 changes in steps. When controlling the first dew point temperature 11 to change in steps, the dehumidification system 1 (controller 30) may keep the airflow of the first fan 112 constant, or it may change the airflow of the first fan 112 in steps. Modifications of Embodiment 1 include a control method in which the first dew point temperature 11 is changed in steps and the airflow of the first fan 112 is kept constant (first modification), and a control method in which both the first dew point temperature 11 and the airflow of the first fan 112 are changed in steps (second modification). The details of the first modification and the second modification will be described below.

[0052] 1-4-1. First variation 1-4-1-1. Example of Controller Functional Configuration Figure 5 is a block diagram showing an example of the functional configuration of controller 30A according to the first modified example of Embodiment 1. Controller 30A includes a room occupancy estimation unit 210, an air supply dew point temperature setting control unit 240, and an equipment drive control unit 230A. The room occupancy estimation unit 210 is the same as described above, so its explanation is omitted here.

[0053] The supply air dew point temperature setting control unit 240 includes a set supply air dew point temperature state determination unit 241 and a set supply air dew point temperature setting unit 242. The set supply air dew point temperature state determination unit 241 determines the state of the set dew point temperature SP based on the number of occupants N and the second dew point temperature 22. Specifically, the set supply air dew point temperature state determination unit 241 uses the information on the number of occupants N and the information on the second dew point temperature 22 to calculate the discharge absolute humidity S0 using the above-described equations (1) to (4). After calculating the discharge absolute humidity S0, the set supply air dew point temperature state determination unit 241 calculates the set dew point temperature SP based on the discharge absolute humidity S0 and determines the state of the set dew point temperature SP. The state of the set dew point temperature SP is expressed as, for example, OFF, ON1, ON2, ON3. Details of the state of the set dew point temperature SP will be described later.

[0054] The set supply air dew point temperature setting unit 242 sets the set dew point temperature SP for the first dew point temperature 11 based on the state of the set dew point temperature SP determined by the set supply air dew point temperature state determination unit 241. The setting of the set dew point temperature SP is expressed, for example, as a reference value of the set dew point temperature SP (hereinafter referred to as reference SP), reference SP-1°CDP, reference SP-2°CDP, reference SP-3°CDP, etc. Details of the setting of the set dew point temperature SP will be described later.

[0055] In this way, the supply air dew point temperature setting control unit 240 sets the set dew point temperature SP for the first dew point temperature 11 in steps based on the number of occupants N and the second dew point temperature 22. This makes it possible to change the first dew point temperature 11 in steps by making the first dew point temperature 11 follow the set dew point temperature SP.

[0056] The equipment drive control unit 230A performs control to keep the airflow of the first fan 112 constant (first fan airflow adjustment control 231A). The first fan airflow adjustment control 231A controls the airflow of the first fan 112 so that it becomes a predetermined airflow. The predetermined airflow is a fixed value determined in advance, for example, an airflow that is equal to or greater than the minimum airflow Qmin required for ventilation of the low dew point room 20. The equipment drive control unit 230A also performs at least one of the following controls to adjust the airflow of the second fan 124 so that the first dew point temperature 11 follows the set dew point temperature SP (second fan airflow adjustment control 232A), adjust the temperature of the regenerative heater 121 (regenerative heater temperature adjustment control 233A), and adjust the rotation speed of the dehumidifying rotor 101 (dehumidifying rotor rotation speed control 234A).

[0057] When the first fan airflow control 231A sets the airflow of the first fan 112 to a constant value, it generates and outputs a drive control signal (e.g., a PWM signal) to the inverter 113 based on the airflow setting information (fixed value) of the first fan 112. When adjusting the airflow of the second fan 124, the second fan airflow control 232A generates and outputs a drive control signal (e.g., a PWM signal) to the inverter 125 based on the airflow setting information of the second fan 124. When adjusting the temperature of the regenerative heater 121, the regenerative heater temperature control 233A generates and outputs a control signal to the thyristor 122 based on the temperature setting information of the regenerative heater 121. When adjusting the rotational speed of the dehumidifying rotor 101, the dehumidifying rotor rotation speed control 234A generates and outputs a drive control signal (e.g., a PWM signal) to the inverter 102 based on the rotational speed setting information of the dehumidifying rotor 101.

[0058] In this way, the equipment drive control unit 230A controls various devices to keep the airflow of the first fan 112 constant while gradually changing the first dew point temperature 11 to follow the set dew point temperature SP. As a result, even if the number of occupants N changes rapidly in a short period of time, the frequency of controlling the various devices is reduced, and fluctuations in the second dew point temperature 22 in the low dew point chamber 20 can be suppressed. Therefore, the dew point in the low dew point chamber 20 can be stably controlled. The equipment drive control unit 230A is repeatedly executed until the second dew point temperature 22 falls below the target dew point temperature (e.g., -30℃DP).

[0059] Furthermore, the control system in controller 30A may be a cascade control system in which a control loop (also called a major loop) controls the second dew point temperature 22 to be below the target dew point temperature (e.g., -30°C DP), and inside this control loop, a control loop (also called a minor loop) controls various devices to make the first dew point temperature 11 follow the set dew point temperature SP in response to changes in the set dew point temperature SP.

[0060] 1-4-1-2. Example of BE processing Figure 6 is a flowchart showing a processing example of controller 30A according to a first modified example of Embodiment 1.

[0061] In step S200, the controller 30A estimates the number of people N in the room based on the sensor information obtained from the sensor 40. The process then proceeds to step S210.

[0062] In step S210, the controller 30A gradually changes the set dew point temperature SP relative to the first dew point temperature 11 based on the number of occupants N and the second dew point temperature 22. The process then proceeds to step S220.

[0063] In step S220, the controller 30A controls at least one of the second fan 124, the regenerative heater 121, and the dehumidifying rotor 101 based on the set dew point temperature SP, while keeping the airflow of the first fan 112 constant. Specifically, the controller 30A controls the airflow of the first fan 112 to be constant, and at least one of the following controls to make the first dew point temperature 11 follow the set dew point temperature SP: airflow control of the second fan 124, temperature control of the regenerative heater 121, and rotation speed control of the dehumidifying rotor 101.

[0064] 1-4-2. Second variation 1-4-2-1. Example of Controller Functional Configuration Figure 7 is a block diagram showing an example of the functional configuration of controller 30B according to a second modified example of Embodiment 1. Controller 30B includes a room occupancy estimation unit 210, an airflow calculation unit 220, an air supply dew point temperature setting control unit 240B, and an equipment drive control unit 230B. The room occupancy estimation unit 210 and the airflow calculation unit 220 are the same as those described above, so their explanation is omitted here.

[0065] The supply air dew point temperature setting control unit 240B includes a set supply air dew point temperature state determination unit 241 and a set supply air dew point temperature setting unit 242. The set supply air dew point temperature state determination unit 241 determines the state of the set dew point temperature SP and the set airflow rate SP based on the amount of dehumidified air Q calculated by the airflow rate calculation unit 220, the second dew point temperature 22, and the target dew point temperature of the second dew point temperature 22 (hereinafter simply referred to as the target dew point temperature). Specifically, the set supply air dew point temperature state determination unit 241 determines the state of the set airflow rate SP for the first fan 112 based on the amount of dehumidified air Q, so that the airflow of the first fan 112 approaches the amount of dehumidified air Q. Furthermore, the set air supply dew point temperature state determination unit 241 determines the state of the set dew point temperature SP relative to the first dew point temperature 11 supplied to the low dew point chamber 20, based on the deviation between the second dew point temperature 22 and the target dew point temperature, so as to bring the second dew point temperature 22 closer to the target dew point temperature. Details of the state of the set dew point temperature SP will be described later.

[0066] The set supply air dew point temperature setting unit 242 sets the set airflow rate SP for the first fan 112 and the set dew point temperature SP for the first dew point temperature 11 based on the state of the set dew point temperature SP determined by the set supply air dew point temperature state determination unit 241. The setting of the set dew point temperature SP (set airflow rate SP) is expressed, for example, as a reference value of the set dew point temperature SP (set airflow rate SP) (hereinafter referred to as reference SP), reference SP-1℃DP, reference SP-2℃DP, reference SP-3℃DP, etc. Details of the setting of the set dew point temperature SP (set airflow rate SP) will be described later.

[0067] In this way, the supply air dew point temperature setting control unit 240B gradually changes the set dew point temperature SP for the first dew point temperature 11 based on the second dew point temperature 22 and the target dew point temperature. Also, the supply air dew point temperature setting control unit 240B gradually changes the set airflow rate SP for the first fan 112 based on the amount of dehumidified air Q. This makes it possible to gradually change the first dew point temperature 11 and the airflow rate of the first fan 112.

[0068] The equipment drive control unit 230B performs control (first fan airflow adjustment control 231B) to adjust the airflow of the first fan 112 based on the set airflow SP. Specifically, the first fan airflow adjustment control 231B gradually changes the airflow of the first fan 112 to follow the set airflow SP. By gradually changing the airflow of the first fan 112, even if the number of occupants N changes rapidly, the frequency of switching the airflow of the first fan 112 is reduced, thereby suppressing fluctuations in the second dew point temperature 22 in the low dew point chamber 20. Therefore, the dew point in the low dew point chamber 20 can be stably controlled.

[0069] Furthermore, the equipment drive control unit 230B performs at least one of the following controls based on the set dew point temperature SP: a control that adjusts the airflow of the second fan 124 (second fan airflow adjustment control 232B) to make the first dew point temperature 11 follow the set dew point temperature SP; a control that adjusts the temperature of the regenerative heater 121 (regenerative heater temperature adjustment control 233B); and a control that adjusts the rotation speed of the dehumidifying rotor 101 (dehumidifying rotor rotation speed control 234B).

[0070] When adjusting the airflow of the first fan 112, the first fan airflow control 231B generates and outputs a drive control signal (e.g., a PWM signal) to the inverter 113 based on the airflow setting information of the first fan 112. When adjusting the airflow of the second fan 124, the second fan airflow control 232B generates and outputs a drive control signal (e.g., a PWM signal) to the inverter 125 based on the airflow setting information of the second fan 124. When adjusting the temperature of the regenerative heater 121, the regenerative heater temperature control 233B generates and outputs a control signal to the thyristor 122 based on the temperature setting information of the regenerative heater 121. When adjusting the rotational speed of the dehumidifying rotor 101, the dehumidifying rotor rotation speed control 234B generates and outputs a drive control signal (e.g., a PWM signal) to the inverter 102 based on the rotational speed setting information of the dehumidifying rotor 101.

[0071] In this way, the equipment drive control unit 230B controls various devices based on the set dew point temperature SP (set airflow SP) which changes in stages. As a result, even if the number of occupants N changes in a short period of time, the frequency of controlling various devices is reduced, and fluctuations in the second dew point temperature 22 in the low dew point room 20 can be suppressed. Therefore, the dew point in the low dew point room 20 can be controlled stably. The equipment drive control unit 230B is repeatedly executed until the second dew point temperature 22 falls below the target dew point temperature (e.g., -30℃ DP).

[0072] Furthermore, the control system in controller 30B may be a cascade control system comprising a control loop (also called a major loop) that controls the second dew point temperature 22 to be below the target dew point temperature (e.g., -30°C DP), a control loop (also called a minor loop) that controls various devices to make the first dew point temperature 11 follow the set dew point temperature SP in response to changes in the set dew point temperature SP, and a control loop (also called a minor loop) that controls the airflow rate of the first fan 112 to make the airflow rate of the first fan 112 follow the set airflow rate SP in response to changes in the set airflow rate SP.

[0073] 1-4-2-2. Example of BE processing Figure 8 is a flowchart showing a processing example of controller 30B according to a second modified example of Embodiment 1.

[0074] In step S300, the controller 30B calculates the discharge absolute humidity S0 based on the first dew point temperature 11. The process then proceeds to step S320.

[0075] In step S310, the controller 30B estimates the number of people N in the room based on the sensor information obtained from the sensor 40. The process then proceeds to step S320.

[0076] In step S320, the controller 30B calculates the amount of dehumidified air Q to be supplied to the low dew point room 20 based on the number of occupants N and the discharge absolute humidity S0. The process then proceeds to step S330.

[0077] In step S330, the controller 30B determines whether the dehumidified air volume Q is equal to or greater than the minimum airflow rate Qmin. If it is determined that the dehumidified air volume Q is equal to or greater than the minimum airflow rate Qmin (step S330; Yes), the process proceeds to step S340. Otherwise (step S330; No), the process proceeds to step S370.

[0078] In step S340, the controller 30B sets and gradually changes the set dew point temperature SP (set airflow rate SP) based on the dehumidified air volume Q, the second dew point temperature 22, and the target dew point temperature. The process then proceeds to step S350. Here, an example of setting the set airflow rate SP is described. Based on the deviation between the second dew point temperature 22 and the target dew point temperature, the controller 30B calculates the airflow rate Qd required to bring the second dew point temperature 22 closer to the target dew point temperature. If the dehumidified air volume Q is greater than or equal to the airflow rate Qd, the controller 30B gradually sets the set airflow rate SP based on the dehumidified air volume Q. If the dehumidified air volume Q is less than the airflow rate Qd, the controller 30B gradually sets the set airflow rate SP based on the airflow rate Qd.

[0079] In step S350, the controller 30B controls various devices based on the set dew point temperature SP (set airflow SP). The process then proceeds to step S360.

[0080] In step S360, the controller 30B determines whether the second dew point temperature 22 is below the target dew point temperature. If it is determined that the second dew point temperature 22 is below the target dew point temperature (step S360; Yes), the process ends. Otherwise (step S360; No), the process returns to step S340. In other words, the processes in steps S340 and S350 are repeatedly executed until the second dew point temperature 22 is below the target dew point temperature.

[0081] In step S370, the controller 30B fixes the airflow of the first fan 112 to the minimum airflow Qmin and outputs it. The process then proceeds to step S360.

[0082] 1-4-3. Set dew point temperature SP (set air volume SP) Details of the set dew point temperature SP (set airflow SP) related to the first and second modified examples will be explained. The set dew point temperature SP (set airflow SP) is set based on the number of occupants N when the amount of dehumidified air Q is equal to or greater than the minimum airflow Qmin, and the second dew point temperature 22 is higher than the target dew point temperature. There are various examples of setting the set dew point temperature SP. Below, two examples of setting the set dew point temperature SP are shown. Here, the number of occupants N when the amount of dehumidified air Q is the minimum airflow Qmin will be explained as X [people]. Also, here, the set dew point temperature SP (set airflow SP) will be simply referred to as "set dew point temperature SP".

[0083] 1-4-3-1. Example of the first setting Figures 9 and 10 are diagrams illustrating a first setting example of the set dew point temperature SP according to a modification of Embodiment 1. In the first setting example, a timer is used to set the set dew point temperature SP. Specifically, the controller 30A (controller 30B) turns on the timer every time the number of occupants N increases or decreases by 3, and sets the set dew point temperature SP based on the number of occupants N after a predetermined time has elapsed since the timer was turned on. The details of the first setting example of the set dew point temperature SP will be described below. The predetermined time refers to, for example, the time set by the timer. The number of occupants N is not limited to an increase or decrease of 3. For example, the number of occupants N may be increased or decreased by a number less than 3, or by a number greater than 3.

[0084] First, let's consider the case where the number of occupants N increases. There are three cases in which the number of occupants N increases, as shown in Figure 9. Specifically, Case 1 is when the number of occupants N increases to or above the second threshold (e.g., X + 3 [people]). In this case, the set air supply dew point temperature state determination unit 241 turns on the first timer, and if the number of occupants N after a predetermined time has elapsed since the first timer was turned on is equal to or above the second threshold, it switches the state of the set dew point temperature SP from OFF to ON1. If the number of occupants N after a predetermined time has elapsed since the first timer was turned on is less than the second threshold, the set air supply dew point temperature state determination unit 241 maintains the state of the set dew point temperature SP at OFF.

[0085] Case 2 is when the number of occupants N increases to or above the third threshold (e.g., X + 6 [people]). In this case, the set air supply dew point temperature state determination unit 241 turns on the second timer, and if the number of occupants N after a predetermined time has elapsed since the second timer was turned on is greater than or equal to the third threshold, the state of the set dew point temperature SP is switched from ON1 to ON2. If the number of occupants N after a predetermined time has elapsed since the second timer was turned on is less than the third threshold, the set air supply dew point temperature state determination unit 241 maintains the state of the set dew point temperature SP at ON1.

[0086] Case 3 is when the number of occupants N increases to or above the fourth threshold (e.g., X + 9 [people]). In this case, the set air supply dew point temperature state determination unit 241 turns on the third timer, and if the number of occupants N after a predetermined time has elapsed since the third timer was turned on is equal to or above the fourth threshold, the state of the set dew point temperature SP is switched from ON2 to ON3. If the number of occupants N after a predetermined time has elapsed since the third timer was turned on is less than the fourth threshold, the set air supply dew point temperature state determination unit 241 maintains the state of the set dew point temperature SP at ON2.

[0087] Furthermore, if the second dew point temperature 22 rises with an increase in the number of occupants N, it is expected that the second dew point temperature 22 will exceed the upper limit of the low dew point chamber 20. For this reason, if the second dew point temperature 22 becomes above a predetermined dew point temperature, the set air supply dew point temperature state determination unit 241 may immediately switch the state of the set dew point temperature SP to lower the second dew point temperature 22. This will cause the second dew point temperature 22 to change from rising to falling, preventing the second dew point temperature 22 from exceeding the upper limit of the low dew point chamber 20.

[0088] Next, let's consider the case where the number of occupants N decreases. There are three cases in which the number of occupants N decreases, as shown in Figure 9. Specifically, Case 1 is when the number of occupants N decreases to less than the first threshold (e.g., X + 3 [people]). In this case, the set air supply dew point temperature state determination unit 241 turns on the first timer, and if the number of occupants N after a predetermined time has elapsed since the first timer was turned on is less than the first threshold, it switches the state of the set dew point temperature SP from ON1 to OFF. If the number of occupants N after a predetermined time has elapsed since the first timer was turned on is greater than or equal to the first threshold, the set air supply dew point temperature state determination unit 241 maintains the state of the set dew point temperature SP at ON1.

[0089] Case 2 is when the number of occupants N decreases to less than the second threshold (e.g., X + 6 [people]). In this case, the set air supply dew point temperature state determination unit 241 turns on the second timer, and if the number of occupants N after a predetermined time has elapsed since the second timer was turned on is less than the second threshold, the state of the set dew point temperature SP is switched from ON2 to ON1. If the number of occupants N after a predetermined time has elapsed since the second timer was turned on is greater than or equal to the second threshold, the set air supply dew point temperature state determination unit 241 maintains the state of the set dew point temperature SP at ON2.

[0090] Case 3 is when the number of occupants N decreases to less than the third threshold (e.g., X + 9 [people]). In this case, the set air supply dew point temperature state determination unit 241 turns on the third timer, and if the number of occupants N after a predetermined time has elapsed since the third timer was turned on is less than the third threshold, the state of the set dew point temperature SP is switched from ON3 to ON2. If the number of occupants N after a predetermined time has elapsed since the third timer was turned on is greater than or equal to the third threshold, the set air supply dew point temperature state determination unit 241 maintains the state of the set dew point temperature SP at ON3.

[0091] Figure 10 is an explanatory diagram showing an example of the change in the first setting of the set dew point temperature SP based on the change in the number of people N in the room. For example, consider the case where, at timing A, the number of people increases to or above the second threshold (X+3 [people]). In this case, the set air supply dew point temperature state determination unit 241 turns on the first timer, and since the number of people N after a predetermined time has elapsed since the first timer was turned on is above the second threshold, it switches the state of the set dew point temperature SP from OFF to ON1. As another example, consider the case where, at timing B, the number of people increases to or above the second threshold (X+6 [people]). In this case, the set air supply dew point temperature state determination unit 241 turns on the second timer, and since the number of people N after a predetermined time has elapsed since the second timer was turned on is above the third threshold, it switches the state of the set dew point temperature SP from ON1 to ON2. As yet another example, consider the case where, at timing C, the number of people decreases to below the second threshold (X+6 [people]). In this case, the set air supply dew point temperature state determination unit 241 turns on the second timer, and since the number of occupants N after a predetermined time has elapsed since the second timer was turned on is less than the second threshold, it switches the state of the set dew point temperature SP from ON2 to ON1. As another example, consider the case at timing D when the number of occupants increases to or above the second threshold (X+6 [people]). In this case, the set air supply dew point temperature state determination unit 241 turns on the second timer, and since the number of occupants N after a predetermined time has elapsed since the second timer was turned on is greater than or equal to the second threshold, it switches the state of the set dew point temperature SP from ON1 to ON2. As yet another example, consider the case at timing E when the number of occupants increases to or above the third threshold (X+9 [people]). In this case, the set air supply dew point temperature state determination unit 241 turns on the third timer, and since the number of occupants N after a predetermined time has elapsed since the third timer was turned on is greater than or equal to the third threshold, it switches the state of the set dew point temperature SP from ON2 to ON3.

[0092] The set air supply dew point temperature setting unit 242 determines the set dew point temperature SP based on the state of the set dew point temperature SP. Specifically, if the state of the set dew point temperature SP is "OFF", the set air supply dew point temperature setting unit 242 sets the set dew point temperature SP as the reference SP.

[0093] The set dew point temperature SP is, for example, expressed as the dew point temperature. In this case, the reference SP is, for example, -40°C DP. The set supply air dew point temperature setting unit 242 sets the set dew point temperature SP as reference SP - 1°C DP (e.g., -41°C DP) when the state of the set dew point temperature SP is "ON1". When the state of the set dew point temperature SP is "ON2", the set supply air dew point temperature setting unit 242 sets the set dew point temperature SP as reference SP - 2°C DP (e.g., -42°C DP). When the state of the set dew point temperature SP is "ON3", the set supply air dew point temperature setting unit 242 sets the set dew point temperature SP as reference SP - 3°C DP (e.g., -43°C DP). The set supply air dew point temperature setting unit 242 sets the set dew point temperature SP in increments of 1°C DP, but is not limited to this. For example, the set air supply dew point temperature setting unit 242 may set the set dew point temperature SP in steps, in increments of a value less than 1°C DP, or it may set the set dew point temperature SP in steps, in increments of a value greater than 1°C DP.

[0094] The set dew point temperature SP may also be expressed in terms of airflow rate. In this case, the set dew point temperature SP is referred to as the set airflow rate SP. The set supply air dew point temperature state determination unit 241 is referred to as the set supply airflow rate state determination unit 241, and the set supply air dew point temperature setting unit 242 is referred to as the set supply airflow rate setting unit 242. The reference SP based on the set airflow rate SP is expressed, for example, as the minimum airflow rate Qmin. When the state of the set airflow rate SP is "ON1", the set supply airflow rate setting unit 242 sets the set airflow rate SP to a value higher than the reference SP (e.g., minimum airflow rate Qmin × 1.2, i.e., an airflow rate increased by 20% from the minimum airflow rate Qmin). When the state of the set airflow rate SP is "ON2", the set supply airflow rate setting unit 242 sets the set airflow rate SP to a value higher than the set airflow rate SP set in ON1 (e.g., minimum airflow rate Qmin × 1.4, i.e., an airflow rate increased by 40% from the minimum airflow rate Qmin). When the state of the set airflow SP is "ON3", the set air supply airflow setting unit 242 sets the set airflow SP to a value higher than the set airflow SP set in ON2 (e.g., minimum airflow Qmin × 1.6, i.e., an airflow that is 60% higher than the minimum airflow Qmin). The set air supply airflow setting unit 242 sets the set airflow SP in steps so as to increase the airflow rate in 20% increments, but is not limited to this. For example, the set air supply airflow setting unit 242 may set the set airflow SP in increments smaller than 20%, or in increments larger than 20%.

[0095] In this way, by using a timer to set the set dew point temperature SP (set airflow SP) in stages, the set dew point temperature SP (set airflow SP) can be set in stages even when the number of people N in the room fluctuates, and the airflow of the first fan 112 can stably follow the set dew point temperature SP (set airflow SP). Therefore, the dew point in the low dew point room 20 can be stably controlled.

[0096] 1-4-3-2. Second Example Figures 11 and 12 illustrate a second example of setting the dew point temperature SP according to a modified example of Embodiment 1. In the second example, a dead zone is used when setting the dew point temperature SP. Specifically, the controller 30A sets the dew point temperature SP each time the number of occupants N increases or decreases by 3. The details of the second example of setting the dew point temperature SP will be described below.

[0097] First, let's consider the case where the number of occupants N increases. There are three cases in which the number of occupants N increases, as shown in Figure 11. Specifically, Case 1 is when the number of occupants N increases to or above the second threshold (e.g., X+3 [people]). In this case, the set air supply dew point temperature state determination unit 241 switches the state of the set dew point temperature SP from OFF to ON1. Case 2 is when the number of occupants N increases to or above the third threshold (e.g., X+6 [people]). In this case, the set air supply dew point temperature state determination unit 241 switches the state of the set dew point temperature SP from ON1 to ON2. Case 3 is when the number of occupants N increases to or above the fourth threshold (e.g., X+9 [people]). In this case, the set air supply dew point temperature state determination unit 241 switches the state of the set dew point temperature SP from ON2 to ON3.

[0098] Next, let's consider the case where the number of occupants N decreases. As shown in Figure 11, there are three cases in which the number of occupants N decreases. Specifically, Case 1 is when the number of occupants N decreases to less than the first threshold (e.g., X [people]). In this case, the set supply air dew point temperature state determination unit 241 switches the state of the set dew point temperature SP from ON1 to OFF. Case 2 is when the number of occupants N decreases to less than the second threshold (e.g., X + 3 [people]). In this case, the set supply air dew point temperature state determination unit 241 switches the state of the set dew point temperature SP from ON2 to ON1. Case 3 is when the number of occupants N decreases to less than the third threshold (e.g., X + 6 [people]). In this case, the set supply air dew point temperature state determination unit 241 switches the state of the set dew point temperature SP from ON3 to ON2.

[0099] Figure 12 is an explanatory diagram showing an example of the change in the setting of the set dew point temperature SP based on a change in the number of occupants N. For example, consider the case where the number of occupants increases to the second threshold (X+3 [people]) or more at timing A. In this case, the set supply air dew point temperature state determination unit 241 switches the state of the set dew point temperature SP from OFF to ON1. As another example, consider the case where the number of occupants increases to the second threshold (X+6 [people]) or more at timing B. In this case, the set supply air dew point temperature state determination unit 241 switches the state of the set dew point temperature SP from ON1 to ON2. As yet another example, consider the case where the number of occupants increases to the third threshold (X+9 [people]) or more at timing C. In this case, the set supply air dew point temperature state determination unit 241 switches the state of the set dew point temperature SP from ON2 to ON3.

[0100] The set supply air dew point temperature setting unit 242 determines the set dew point temperature SP based on the state of the set dew point temperature SP. The details of the set supply air dew point temperature setting unit 242 are the same as in the first setting example described above, so the explanation is omitted here. In the second setting example, the set dew point temperature SP may be expressed in terms of airflow rate, as in the first setting example described above. In this case, "set dew point temperature SP" is read as "set airflow rate SP", "set supply air dew point temperature state determination unit 241" is read as "set supply airflow rate state determination unit 241", and "set supply air dew point temperature setting unit 242" is read as "set supply airflow rate setting unit 242".

[0101] In this way, by setting the set dew point temperature SP (set airflow SP) in stages using a dead zone, the set dew point temperature SP (set airflow SP) can be set in stages even when the number of people N in the room fluctuates. This allows the first dew point temperature 11 to stably follow the set dew point temperature SP, or the airflow of the first fan 112 to stably follow the set airflow SP. Therefore, the dew point in the low dew point room 20 can be stably controlled.

[0102] 1-4-4. Fan airflow Figure 13 is a diagram illustrating an example of setting the fan airflow according to a second modification of Embodiment 1. After setting the set airflow SP, the device drive control unit 230B sets the airflow of the first fan 112 according to the set airflow SP. Specifically, as shown in Figure 13, when the setting value of the set airflow SP is "OFF", the device drive control unit 230B sets the airflow of the first fan 112 to the minimum airflow Qmin. When the setting value of the set airflow SP is "ON1", the device drive control unit 230B sets the airflow of the first fan 112 to the minimum airflow Qmin × 1.2, that is, an airflow that is 20% higher than the minimum airflow Qmin. When the setting value of the set airflow SP is "ON2", the device drive control unit 230B sets the airflow of the first fan 112 to the minimum airflow Qmin × 1.4, that is, an airflow that is 40% higher than the minimum airflow Qmin. When the setting value of the set airflow SP is "ON3", the device drive control unit 230B sets the airflow of the first fan 112 to the minimum airflow Qmin × 1.6, that is, an airflow that is 60% higher than the minimum airflow Qmin. Note that the airflow of the first fan 112 is set to an airflow that is increased by 20% increments from the minimum airflow Qmin (Qmin × 1.2, Qmin × 1.4, Qmin × 1.6, ...), but is not limited to this. For example, the airflow of the first fan 112 may be set to an airflow that is increased by less than 20% increments from the minimum airflow Qmin (e.g., Qmin × 1.1, Qmin × 1.2, Qmin × 1.3, ...), or it may be set to an airflow that is increased by more than 20% increments from the minimum airflow Qmin (e.g., Qmin × 1.25, Qmin × 1.5, Qmin × 1.75, ...).

[0103] As another example, if the setting value of the set airflow SP changes from "ON3" to "ON2", the device drive control unit 230B sets the airflow of the first fan 112 to the minimum airflow Qmin × 1.4, that is, an airflow that is 20% less than the airflow of the first fan 112 set in ON3. If the setting value of the set airflow SP changes from "ON2" to "ON1", the device drive control unit 230B sets the airflow of the first fan 112 to the minimum airflow Qmin × 1.2, that is, an airflow that is 20% less than the airflow of the first fan 112 set in ON2. If the setting value of the set airflow SP changes from "ON1" to "OFF", the device drive control unit 230B sets the airflow of the first fan 112 to the minimum airflow Qmin, that is, an airflow that is 20% less than the airflow of the first fan 112 set in ON1. Furthermore, while the device drive control unit 230B is set to increase the airflow of the first fan 112 in increments of 20%, it is not limited to this. For example, the device drive control unit 230B may be set to increase the airflow of the first fan 112 in increments of less than 20%, or it may be set to increase the airflow of the first fan 112 in increments of more than 20%.

[0104] According to a second modification of Embodiment 1, the equipment drive control unit 230B sets the airflow of the first fan 112 to increase or decrease in stages based on the set airflow SP. The airflow of the first fan 112 is set to change in stages. By changing the airflow of the first fan 112 in stages, even if the number of occupants N changes in a short period of time, the frequency of switching the airflow of the first fan 112 is reduced, so that fluctuations in the second dew point temperature 22 in the low dew point chamber 20 can be suppressed. Therefore, the dew point in the low dew point chamber 20 can be stably controlled.

[0105] 1-5. Effects In the dehumidification system 1 (dehumidification system 1A) according to Embodiment 1, at least one of the first dew point temperature 11 and the airflow rate of the first fan is changed in steps based on at least the number of occupants N and the second dew point temperature 22. As a result, even if the number of occupants N changes in a short period of time, fluctuations in the second dew point temperature 22 in the low dew point chamber 20 can be suppressed. Therefore, the dew point in the low dew point chamber 20 can be stably controlled.

[0106] 2. Embodiment 2 2-1. Example of a dehumidification system configuration Figure 14 is a diagram illustrating an example of the configuration of the dehumidification system 1B according to Embodiment 2. In addition to the configuration of the dehumidification system 1 according to Embodiment 1 described above, the dehumidification system 1B further includes an airflow control device 50, a control valve 60, and a pressure gauge 70.

[0107] The airflow control device 50 is located in the first duct 131 on the outlet side of the first area of ​​the dehumidifying rotor 101. The airflow control device 50 adjusts the airflow rate of the dehumidified air flowing through the first duct 131. The airflow control device 50 is, for example, a VAV (Variable Air Volume system). When changing the airflow rate of the dehumidified air, the dehumidification system 1B may adjust the airflow rate of the airflow control device 50 while keeping the airflow rate of the first fan 112 constant, or it may adjust the airflow rates of both the first fan 112 and the airflow control device 50. In this way, when increasing or decreasing the airflow rate of the dehumidified air, at least the airflow rate of the airflow control device 50 is adjusted.

[0108] The control valve 60 is located in the third duct 133A. The third duct 133A is a pipe in which one end is connected to connection point a in the first duct 131 between the airflow control device 50 and the outlet side of the first area of ​​the dehumidifying rotor 101, and the other end is connected to the exhaust port. Based on the airflow pressure information in the first duct 131 obtained by the pressure gauge 70, the control valve 60 adjusts the airflow pressure on the outlet side of the first area of ​​the dehumidifying rotor 101 in the first duct 131.

[0109] Now, let's consider the case where the airflow rate of the dehumidified air is adjusted by the airflow control device 50. In this case, if a pressure loss occurs in the first duct 131, it may not be possible to supply a sufficient amount of dehumidified air Q to the low dew point chamber 20, and the second dew point temperature 22 in the low dew point chamber 20 may fluctuate.

[0110] According to the dehumidification system 1B of Embodiment 2, the controller 30C performs control (also referred to as first control) that changes the airflow rate of the airflow control device 50 in steps based on the estimated number of occupants and the first dew point temperature 11. The controller 30C also performs control (also referred to as second control) that changes the airflow rate of the airflow control device 50 in steps based on the second dew point temperature 22. Furthermore, while the first and second controls are being performed, the controller 30C controls the opening and closing of the adjustment valve 60 to maintain the airflow pressure inside the first duct 131 (the outlet side of the first area of ​​the dehumidification rotor 101) at a reference value. For example, when the number of occupants N decreases, the airflow rate of the airflow control device 50 is reduced and the airflow pressure increases. In this case, the opening of the adjustment valve 60 increases, which increases the bypass flow rate passing through the third duct 133A, enabling stable airflow control without adjusting the airflow rate of the first fan 112. This suppresses pressure loss in the first duct 131, allowing for a stable supply of dehumidified air Q to the low dew point chamber 20. Therefore, even when the number of occupants N increases, fluctuations in the second dew point temperature 22 within the low dew point chamber 20 can be suppressed, enabling stable control of the dew point within the low dew point chamber 20. The reference value is, for example, a pressure value at which no pressure loss occurs within the first duct 131. This reference value is, for example, a predetermined fixed value. Details of the various controls performed by the controller 30C will be described later.

[0111] 2-2. Example of Controller Functional Configuration Figure 15 is a block diagram showing an example of the functional configuration of the controller 30C according to Embodiment 2. The controller 30C includes a room occupancy estimation unit 210, an airflow calculation unit 220, and an equipment drive control unit 230C. The room occupancy estimation unit 210 and the airflow calculation unit 220 are the same as those described above, so their explanation is omitted here.

[0112] The equipment drive control unit 230C includes controls for adjusting the airflow of the first fan 112 (first fan airflow adjustment control 231C), controls for adjusting the airflow of the second fan 124 (second fan airflow adjustment control 232C), controls for adjusting the temperature of the regenerative heater 121 (regenerative heater temperature adjustment control 233C), controls for adjusting the rotation speed of the dehumidifying rotor 101 (dehumidifying rotor rotation speed control 234C), controls for adjusting the airflow of the airflow control device 50 (VAV airflow adjustment control 235C), and a blower pressure control 236C. The first fan airflow adjustment control 231C adjusts the airflow of the first fan 112 to be constant or to change the airflow of the first fan 112 in steps, based on the amount of dehumidified air Q obtained by the airflow calculation unit 220 and the second dew point temperature 22. For example, if the amount of dehumidified air flowing through the first duct 131 can be brought close to the amount of dehumidified air Q simply by adjusting the airflow control device 50, the first fan airflow control 231C adjusts the airflow of the first fan 112 to be constant. In another example, if the amount of dehumidified air flowing through the first duct 131 cannot be brought close to the amount of dehumidified air Q simply by adjusting the airflow control device 50, the first fan airflow control 231C adjusts the airflow of the first fan 112 to change in steps.

[0113] The VAV airflow control 235C adjusts the airflow of the airflow control device 50 in steps based on the amount of dehumidified air Q obtained by the airflow calculation unit 220 and the second dew point temperature 22. By changing the airflow of the airflow control device 50 in steps, even if the number of occupants N changes rapidly in a short period of time, the frequency of switching the airflow of the airflow control device 50 is reduced, thereby suppressing fluctuations in the second dew point temperature 22 in the low dew point room 20. Therefore, the dew point in the low dew point room 20 can be stably controlled.

[0114] The second fan airflow control 232C, the regenerative heater temperature control 233C, and the dehumidifying rotor rotation speed control 234C are executed when the first dew point temperature 11 is kept constant or when the first dew point temperature 11 is changed in steps. The control of various devices (first fan airflow control 231C, second fan airflow control 232C, regenerative heater temperature control 233C, dehumidifying rotor rotation speed control 234C, VAV airflow control 235C, and blower pressure control 236C) is repeatedly executed until the second dew point temperature 22 is below the target dew point temperature (e.g., -30℃DP).

[0115] The air pressure control system 236C controls the opening and closing of the adjustment valve 60 to maintain a constant air pressure in the first duct 131, based on the air pressure information of the first duct 131 obtained from the pressure gauge 70. This suppresses a decrease in the airflow rate of the dehumidified air flowing through the first duct 131. The details of the air pressure control system 236C will be described below with reference to Figure 16.

[0116] Figure 16 is a diagram illustrating an example of opening control of the regulating valve 60 according to Embodiment 2. Specifically, as shown in Figure 16, when the air pressure of the first duct 131 is above a reference value, the air pressure control 236C sets the opening value of the regulating valve 60 to a value greater than the current value (open direction) in order to lower the air pressure of the first duct 131. This allows a portion of the airflow of dehumidified air flowing through the first duct 131 to escape to the third duct 133A, thereby lowering the air pressure of the first duct 131. Consequently, the air pressure of the first duct 131 is maintained at the reference value, and fluctuations in the second dew point temperature 22 in the low dew point chamber 20 can be suppressed.

[0117] As another example, consider the case where the air pressure in the first duct 131 is below the reference value. In this case, a pressure loss occurs in the first duct 131, so the air pressure control 236C sets the opening value of the adjustment valve 60 to a value smaller than the current value (closed direction) to increase the air pressure in the first duct 131, as shown in Figure 16. This makes it possible to increase the air pressure in the first duct 131. Therefore, the air pressure in the first duct 131 can be appropriately maintained, for example, to the reference value, and fluctuations in the second dew point temperature 22 in the low dew point chamber 20 can be suppressed.

[0118] 2-3. Example of controller processing As described above, the first fan airflow control 231C adjusts the airflow of the first fan 112 to be constant, or adjusts the airflow of the first fan 112 to be changed in steps. Here, the processing example of the controller 30C when the airflow of the first fan 112 is kept constant by the first fan airflow control 231C is referred to as the first processing example. On the other hand, the processing example of the controller 30C when the airflow of the first fan 112 is changed in steps by the first fan airflow control 231C is referred to as the second processing example. The following describes each processing example.

[0119] 2-3-1. First Processing Example Figure 17 is a flowchart showing a first processing example of the controller 30C according to Embodiment 2.

[0120] In step S400, the controller 30C calculates the discharge absolute humidity S0 based on the first dew point temperature 11. The process then proceeds to step S420.

[0121] In step S410, the controller 30C estimates the number of people N in the room based on the sensor information obtained from the sensor 40. The process then proceeds to step S420.

[0122] In step S420, the controller 30C calculates the amount of dehumidified air Q to be supplied to the low dew point room 20 based on the number of occupants N and the discharge absolute humidity S0. The process then proceeds to steps S430 and S440.

[0123] In step S430, the controller 30C gradually changes the airflow rate of the airflow control device 50. The controller 30C also controls the opening and closing of the regulating valve 60 to keep the airflow pressure in the first duct 131 constant. The process then proceeds to step S450.

[0124] In step S440, the controller 30C adjusts the airflow of the first fan 112 to a constant level. The process then proceeds to step S450.

[0125] In step S450, the controller 30C determines whether the second dew point temperature 22 is below the target dew point temperature. If it is determined that the second dew point temperature 22 is below the target dew point temperature (step S450; Yes), the process ends. Otherwise (step S450; No), the process returns to steps S430 and S440. In other words, the control that gradually changes the airflow rate of the airflow control device 50 (VAV airflow rate adjustment control 235C) and the control that keeps the airflow rate of the first fan 112 constant (first fan airflow rate adjustment control 231C) are repeatedly executed until the second dew point temperature 22 is below the target dew point temperature.

[0126] 2-3-2. Second Processing Example Figure 18 is a flowchart showing a second processing example of the controller 30C according to Embodiment 2.

[0127] In step S500, the controller 30C calculates the discharge absolute humidity S0 based on the first dew point temperature 11. The process then proceeds to step S520.

[0128] In step S510, the controller 30C estimates the number of people N in the room based on the sensor information obtained from the sensor 40. The process then proceeds to step S520.

[0129] In step S520, the controller 30C calculates the amount of dehumidified air Q to be supplied to the low dew point room 20 based on the number of occupants N and the discharge absolute humidity S0. The process then proceeds to steps S530 and S540.

[0130] In step S530, the controller 30C determines whether the dehumidified air volume Q is equal to or greater than the minimum airflow rate Qmin. If it is determined that the dehumidified air volume Q is equal to or greater than the minimum airflow rate Qmin (step S530; Yes), the process proceeds to step S550. Otherwise (step S530; No), the process proceeds to step S560.

[0131] In step S540, the controller 30C gradually changes the airflow rate of the airflow control device 50. The process then proceeds to step S570.

[0132] In step S550, controller 30C gradually changes the airflow rate of the first fan 112. Controller 30B also controls the opening and closing of the regulating valve 60 to maintain the air pressure in the first duct 131 at a reference value. The process then proceeds to step S570.

[0133] In step S560, the controller 30C fixes the airflow of the first fan 112 to the minimum airflow Qmin and controls the opening and closing of the control valve 60 to maintain the air pressure in the first duct 131 at a reference value. The process then proceeds to step S570.

[0134] In step S570, the controller 30C determines whether the second dew point temperature 22 is below the target dew point temperature. If it is determined that the second dew point temperature 22 is below the target dew point temperature (step S570; Yes), the process ends. Otherwise (step S570; No), the process returns to steps S540 and S550. In other words, the airflow control of the airflow control device 50 (VAV airflow adjustment control 235C), the airflow control of the first fan 112 (first fan airflow adjustment control 231C), and the opening and closing control of the control valve 60 are repeatedly performed until the second dew point temperature 22 is below the target dew point temperature.

[0135] 3. Embodiment 3 Figure 19 is a diagram illustrating an example configuration of the dehumidification system 1C according to Embodiment 3. In the dehumidification system 1 according to Embodiment 1 and the dehumidification system 1B according to Embodiment 2 described above, the "low dew point chamber 20" is a single chamber, but is not limited to this. For example, the "low dew point chamber 20" may be multiple low dew point chambers 20. In the dehumidification system 1C according to Embodiment 3, the piping branched at connection point b shown in Figure 19 is connected to each low dew point chamber 20 (e.g., first low dew point chamber 20A, second low dew point chamber 20B, third low dew point chamber 20C), and a single dry dehumidifier 100 is used to supply a dehumidified air volume Q to each low dew point chamber 20. Furthermore, an airflow control device 50 (e.g., a first airflow control device 50A, a second airflow control device 50B, and a third airflow control device 50C) corresponding to each low dew point chamber 20 is provided, and the dehumidification system 1C (controller 30D) adjusts the amount of air supplied to each low dew point chamber 20 using each airflow control device 50. As a result, it is not necessary to provide a dry dehumidifier 100 for each low dew point chamber 20, thus reducing costs. Below, an example of the processing of the controller 30D according to Embodiment 3 will be explained using the case in which the "low dew point chamber 20" in the dehumidification system 1B according to Embodiment 2 is a plurality of low dew point chambers 20 as an example.

[0136] Figure 20 is a flowchart showing an example of processing by the controller 30D according to Embodiment 3.

[0137] In step S600, the controller 30D calculates the discharge absolute humidity S0 based on the first dew point temperature 11. The process then proceeds to step S620.

[0138] In step S610, the controller 30D estimates the number of occupants N in each room based on sensor information obtained from sensors 40 installed in each room. For example, consider the case where there are three low dew point rooms 20 (first low dew point room 20A, second low dew point room 20B, and third low dew point room 20C). In this case, the controller 30D estimates the number of occupants N1 in the first low dew point room 20A based on sensor information obtained from sensor 40A installed in the first low dew point room 20A. The process then proceeds to step S620. The controller 30D also estimates the number of occupants N2 in the second low dew point room 20B based on sensor information obtained from sensor 40B installed in the second low dew point room 20B. The process then proceeds to step S630. Furthermore, the controller 30D estimates the number of occupants N3 in the third low dew point room 20C based on sensor information obtained from the sensor 40C installed in the third low dew point room 20C. The process then proceeds to step S640.

[0139] In step S620, the controller 30D calculates the amount of dehumidified air Q1 to be supplied to the first low dew point room 20A based on the number of occupants N1 and the discharge absolute humidity S0. The process then proceeds to step S650.

[0140] In step S630, the controller 30D calculates the amount of dehumidified air Q2 to be supplied to the second low dew point room 20B based on the number of occupants N2 and the discharge absolute humidity S0. The process then proceeds to step S650.

[0141] In step S640, the controller 30D calculates the amount of dehumidified air Q3 to be supplied to the third low dew point room 20C based on the number of occupants N2 and the discharge absolute humidity S0. The process then proceeds to step S650.

[0142] In step S650, the controller 30D calculates the total amount of dehumidified air Qsum, which is the sum of the dehumidified air amounts Q(Q1, Q2, Q3) in each room. The process then proceeds to steps S660 and S670.

[0143] In step S660, the controller 30D determines whether the total amount of dehumidified air Qsum is equal to or greater than the minimum airflow rate Qmin. If it is determined that the total amount of dehumidified air Qsum is equal to or greater than the minimum airflow rate Qmin (step S660; Yes), the process proceeds to step S550 shown in Figure 18. Otherwise (step S660; No), the process proceeds to step S560 shown in Figure 18.

[0144] In step S670, the controller 30D gradually changes the airflow of the airflow control device 50 corresponding to each room. The process then proceeds to step S570, as shown in Figure 18.

[0145] According to Embodiment 3, the controller 30D estimates the number of occupants N (number of occupants N1, number of occupants N2, number of occupants N3) in each low dew point chamber 20. After estimating the number of occupants N in each chamber, the controller 30D gradually changes the airflow rate of the first fan 112 based on the estimated number of occupants N in each chamber and the first dew point temperature 11, or gradually changes the airflow rate of the airflow control device 50 corresponding to each chamber while keeping the airflow rate of the first fan 112 constant, or gradually changes the airflow rates of both the first fan 112 and the airflow control device 50 corresponding to each chamber. This makes it possible to suppress fluctuations in the second dew point temperature 22 in the low dew point chamber 20 even when the number of occupants N in each chamber changes. The controller 30D may also control the opening and closing of the adjustment valve 60 to maintain the airflow pressure inside the first duct 131 (the outlet side of the first area of ​​the dehumidifying rotor 101) at a reference value. This makes it possible to suppress pressure loss in the first duct 131. Therefore, the dew point in the low dew point chamber 20 can be stably controlled. [Explanation of Symbols]

[0146] 1, 1A, 1B, 1C… Dehumidification system, 11… First dew point temperature, 20… Low dew point chamber, 20A… First low dew point chamber, 20B… Second low dew point chamber, 20C… Third low dew point chamber, 22… Second dew point temperature, 30, 30A, 30B, 30C, 30D… Controller, 40, 40A, 40B, 40C… Sensor, 50… Airflow control device, 50A… First airflow control device, 50B… Second airflow control device, 50C… Third airflow control device Your device, 60...regulating valve, 70...pressure gauge, 100...dry dehumidifier, 101...dehumidifying rotor, 102...inverter, 110...first filter, 111...precooler, 112...first fan, 113...inverter, 114...aftercooler, 115...afterheater, 120...second filter, 121...regenerative heater, 122...thyristor, 123...thermometer, 124...second fan, 125...inverter 131...First duct, 131A...First branch duct, 132...Second duct, 133,133A...Third duct, 210...Occupancy estimation unit, 220...Air volume calculation unit, 230,230A,230B,230C...Equipment drive control unit, 231,231A,231B,231C...First fan air volume adjustment control, 232,232A,232B,233C...Second fan air volume adjustment control, 233,233 A, 233B, 233C... Regeneration heater temperature control, 234, 234A, 234B... Dehumidification rotor rotation speed control, 235C... Airflow control of airflow control device, 236C... Airflow pressure control, 240, 240B... Supply air dew point temperature setting control unit, 241... Set supply air dew point temperature state determination unit, Set supply airflow state determination unit, 242... Set supply air dew point temperature setting unit, Set supply airflow setting unit, SP... Set dew point temperature, Set airflow

Claims

1. A dehumidification system that supplies low-dew-point air into a low-dew-point room, A dehumidifying rotor having a first area provided in a first duct connected to the low dew point chamber, which adsorbs moisture contained in the air supplied to the low dew point chamber and discharges dehumidified air to the first duct, and a second area provided in a second duct connected to an exhaust port, which discharges humid air containing the adsorbed moisture to the second duct, The first duct includes a fan provided on the inlet side of the first area, which adjusts the airflow rate of the dehumidified air to increase or decrease the amount of air being blown, A sensor is provided in the low dew point chamber to detect a person inside the low dew point chamber, A controller connected to the sensor and the fan, Equipped with, The aforementioned controller, Based on the person detection information obtained by the aforementioned sensor, the number of people in the low dew point chamber is estimated. The system is configured to gradually change at least one of the fan's airflow and the first dew point temperature, which indicates the dew point temperature of the dehumidified air, based on at least the estimated number of people and the second dew point temperature, which indicates the dew point temperature in the low dew point chamber. A dehumidification system characterized by the following features.

2. A dehumidification system according to claim 1, The controller, after estimating the number of people in the low dew point chamber, Based on the estimated number of people, the first dew point temperature, and the second dew point temperature, the amount of dehumidified air supplied to the low dew point chamber is calculated. The system is configured to gradually change the airflow of the fan so that it approaches the amount of dehumidified air. A dehumidification system characterized by the following features.

3. A dehumidification system according to claim 2, An airflow control device provided on the outlet side of the first area in the first duct, which adjusts the airflow rate of the dehumidified air flowing through the first duct, A control valve is provided in a third duct, one end of which is connected to the connection point in the first duct between the airflow control device and the outlet side of the first area, and the other end of which is connected to the exhaust port, and which adjusts the airflow pressure on the outlet side of the first area of ​​the first duct, Furthermore, The controller, after estimating the number of people in the low dew point chamber, Based on the estimated number of people and the first dew point temperature, a first control is performed to change the airflow rate of the airflow control device in steps. Based on the second dew point temperature, a second control is performed to change the airflow rate of the airflow control device in steps. During the execution of the first and second controls, the control valve is opened and closed to maintain the air pressure in the first duct at a reference value. A dehumidification system characterized by the following features.

4. A dehumidification system according to claim 2, An airflow control device provided on the outlet side of the first area in the first duct, which adjusts the airflow rate of the dehumidified air flowing through the first duct, A control valve is provided in a third duct, one end of which is connected to the connection point in the first duct between the airflow control device and the outlet side of the first area, and the other end of which is connected to the exhaust port, and which adjusts the airflow pressure on the outlet side of the first area of ​​the first duct, Furthermore, The controller, after estimating the number of people in the low dew point chamber, Based on the estimated number of people and the first dew point temperature, a first control is performed to change the airflow of the fan and the airflow control device in steps. Based on the second dew point temperature, a second control is performed to change the airflow rate of the airflow control device in steps. During the execution of the first and second controls, the control valve is opened and closed to maintain the air pressure in the first duct at a reference value. A dehumidification system characterized by the following features.

5. A dehumidification system according to claim 1, The controller, after estimating the number of people in the low dew point chamber, Based on the estimated number of people and the second dew point temperature, the set dew point temperature relative to the first dew point temperature is set in stages. The system is configured to gradually change the first dew point temperature so that it follows the set dew point temperature. A dehumidification system characterized by the following features.

6. A dehumidification system according to claim 1, The controller, after estimating the number of people in the low dew point chamber, Based on the estimated number of people, the first dew point temperature, and the second dew point temperature, the set airflow rate for the fan is set in stages. The fan is configured to gradually change its airflow so that it follows the set airflow. A dehumidification system characterized by the following features.

7. A dehumidification system according to claim 1, The aforementioned controller, Based on the estimated number of people and the second dew point temperature, the amount of dehumidified air supplied to the low dew point chamber is calculated. The system is configured to gradually change the airflow of the fan so that it approaches the amount of dehumidified air. A dehumidification system characterized by the following features.

8. A dehumidification system according to claim 1, The aforementioned controller, Based on the estimated number of people and the second dew point temperature, the set dew point temperature relative to the first dew point temperature is calculated. The system is configured to gradually change the first dew point temperature so that it follows the set dew point temperature. A dehumidification system characterized by the following features.

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