Dehumidification system

Abstract

To provide a dehumidification system capable of stably controlling the dew point temperature in a booth, even when the booth requires management at a lower dew point, in a low dew point room. [Solution] The low dew point chamber 20 includes a first low dew point chamber 20A and a second low dew point chamber 20B (booth) located inside the first low dew point chamber 20A and having a lower dew point than the first low dew point chamber 20A. The low dew point chamber 20 is equipped with a desiccant material 41 that absorbs moisture in the air and is located in an air vent between the first low dew point chamber 20A and the second low dew point chamber 20B, and a fan 42 that is located outside the second low dew point chamber 20B across the desiccant material 41 and supplies air from the first low dew point chamber 20A into the second low dew point chamber 20B via the desiccant material 41. The fan 42 is controlled to stop when the door of the second low dew point chamber 20B is closed and to operate when the door is open.

Description

[Technical Field]

[0001] The present disclosure relates to a dehumidification system for controlling the dew point temperature of a low dew point room. [Background technology]

[0002] Patent Document 1 discloses a method for controlling the dew point temperature of a low dew point chamber. According to this control method, the low dew point chamber is adjusted to a positive pressure relative to the outside, and the front chamber is adjusted to a positive pressure relative to the outside and a negative pressure relative to the low dew point chamber. Furthermore, in this control method, an inter-chamber pressure adjustment damper is provided on the side separating the low dew point chamber and the front chamber to mitigate a sudden increase in pressure in the low dew point chamber. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-190989 Summary of the Invention [Problem to be solved by the invention]

[0004] Now, consider a case where a low dew point room contains booths with different dew point temperatures. The booths must be maintained at a lower dew point (e.g., -70°C DP) than the dew point temperature outside the booth (e.g., -40°C DP). In this case, when workers open the door to enter or exit the booth, moisture from outside the booth flows into the booth. This raises the dew point temperature inside the booth, making it difficult to maintain the required dew point temperature.

[0005] One object of the present disclosure is to provide a dehumidification system that can stably control the dew point temperature within a booth in a low dew point room, even if the booth requires management at a lower dew point. [Means for solving the problem]

[0006] One aspect of the present disclosure relates to a dehumidification system for controlling a dew point temperature of a low dew point chamber, the low dew point chamber comprising a first low dew point chamber and a second low dew point chamber disposed inside the first low dew point chamber; It is maintained at a positive pressure relative to the first low dew point chamber, and a second low dew point chamber having a lower dew point than the first low dew point chamber. The low dew point chamber is provided with a desiccant material that absorbs moisture in the air and is installed in the vent between the first and second low dew point chambers, and a fan that is installed outside the second low dew point chamber across the desiccant material and supplies air from the first low dew point chamber into the second low dew point chamber through the desiccant material. The fan is controlled to stop while the door of the second low dew point chamber is closed and to operate while the door is open. [Effects of the Invention]

[0007] According to the present disclosure, the low dew point chamber comprises a first low dew point chamber; It is maintained at a positive pressure relative to the first low dew point chamber, The system includes a second low dew point chamber with a lower dew point than the first low dew point chamber. The low dew point chamber is equipped with a desiccant material that absorbs moisture in the air and a fan that supplies air from the first low dew point chamber to the second low dew point chamber through the desiccant material. The fan is controlled to stop when the door of the second low dew point chamber is closed and to operate when the door is open. This allows the booth to maintain positive pressure relative to the outside of the booth, even if the door of the second low dew point chamber is open for a certain period of time, thereby suppressing the inflow of moisture from outside the booth. Therefore, even if there is a booth within the low dew point chamber that requires management at a lower dew point, the dew point temperature within that booth can be stably controlled. Furthermore, since there is no need to dehumidify the air supplied to the first low dew point chamber to the dew point temperature required for the second low dew point chamber, the power consumption of the dehumidification system can be reduced. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is an explanatory diagram showing an overview of a dehumidification system according to an embodiment; [Figure 2] FIG. 2 is an explanatory diagram showing a specific example of a low dew point chamber according to the embodiment. [Figure 3] FIG. 10 is an explanatory diagram showing an example of a change in dew point temperature in the booth according to the embodiment. [Figure 4]FIG. 10 is an explanatory diagram showing a specific example of a low dew point chamber according to a modified example of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] A dehumidification system according to an embodiment of the present disclosure will be described with reference to the accompanying drawings. Elements common to the drawings will be designated by the same reference numerals, and redundant description will be omitted.

[0010] 1. Example of dehumidification system configuration FIG. 1 is an explanatory diagram showing an overview of a dehumidification system 1 according to an embodiment. The dehumidification system 1 supplies low dew point air to a low dew point chamber 20 (also simply referred to as a room 20). The low dew point chamber 20 includes a first low dew point chamber 20A and a second low dew point chamber 20B. The second low dew point chamber 20B is a booth located inside the first low dew point chamber 20A and required to be managed at a lower dew point than the first low dew point chamber 20A. The first low dew point chamber 20A is also referred to as an "outside booth," and the second low dew point chamber 20B is also referred to as a "booth." The first low dew point chamber 20A is managed within a dew point temperature range of, for example, -50°C DP to -30°C DP. The second low dew point chamber 20B is managed within a dew point temperature range of, for example, -70°C DP to -50°C DP. Examples of the low dew point chamber 20 (first low dew point chamber 20A, second low dew point chamber 20B) include a dry room, a clean room, etc. Details of the internal configuration of the low dew point chamber 20 will be described later.

[0011] The dehumidification system 1 includes a low dew point chamber 20, a dry dehumidifier 100, and a control device 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 regenerative heater 121, a precooler 111, an aftercooler 114, and an afterheater 115.

[0012] The first duct 131 has one end connected to an outside air port and the other end connected to the low dew point chamber 20. The second duct 132 has one end connected to an outside air port and the other end connected to an exhaust port. The outside air port connected to the first duct 131 and the outside air port connected to the second duct 132 may be the same or different. The dehumidification system 1 is also provided with a third duct 133. The third duct 133 is a pipe for allowing return air from the low dew point chamber 20 to flow into the dry dehumidifier 100 and for exhausting the air to the exhaust port. The third duct 133 has one end connected to the low dew point chamber 20 and the other end 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 at an arbitrary rotation speed. The dehumidifying rotor 101 is equipped with a power conversion device 102 (also simply referred to as 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 control device 30.

[0014] The dehumidification rotor 101 has a first area and a second area. The first area has a function of adsorbing moisture contained in mixed air containing outside air drawn in from the outside air port through the first filter 110 and return air from the low dew point chamber 20, and discharging the dehumidified air. The second area has a function of discharging humid air containing the adsorbed moisture and outside air drawn in from the outside air port through the second filter 120. The humid air may contain 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 of ​​the first duct 131 and the inlet side of the second area of ​​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 provided in the first duct 131 on the inlet side of the first area of ​​the dehumidification rotor 101, and sends out mixed air obtained by drawing in outside air from the outside air port and return air from the low dew point chamber 20 toward the inlet side of the first area, and also sends out the mixed air toward the second duct 132 via the first branch duct 131A. The first fan 112 is equipped with a power conversion device 113 (also simply referred to as an inverter 113) for driving the fan. The inverter 113 is controlled by the control device 30.

[0016] The second fan 124 is provided in the second duct 132 on the outlet side of the second area of ​​the dehumidification rotor 101, and draws in outside air from the outside air port and sends it out toward the inlet side of the second area, and also sends out high-temperature, humid air that is exhausted from the outlet side of the second area and heated by the regenerative heater 121 toward the exhaust port. The second fan 124 is equipped with a power conversion device 125 (also simply referred to as inverter 125) for driving the fan. The inverter 125 is controlled by the control device 30. The second fan 124 is also referred to as regenerative fan 124.

[0017] The regenerative heater 121 is provided in the second duct 132 on the inlet side of the second area of ​​the dehumidification rotor 101, and heats the humid air. The regenerative heater 121 is equipped with a thyristor 122 that adjusts the power of the heater. The thyristor 122 is controlled by the control device 30. The temperature of the humid air heated by the regenerative heater 121 is monitored by the control device 30. The temperature of the humid air is measured, for example, by a thermometer 123 (also referred to as thermometer T) provided in the second duct 132 on the inlet side of the second area of ​​the dehumidification rotor 101.

[0018] The precooler 111 is provided in the first duct 131 between the first filter 110 and the first fan 112. The precooler 111 cools outside air taken in from an outside air port or mixed air containing outside air from the outside air port and return air from the low dew point chamber 20. In this case, the precooler 111 may be supplied with cold water for cooling the outside air or mixed air.

[0019] The aftercooler 114 cools the dehumidified air discharged from the dehumidification rotor 101. This makes it possible to suppress a rise in the temperature of the dehumidified air. In this case, the aftercooler 114 may be supplied with cold water for cooling the dehumidified air.

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

[0021] The control device 30 controls the dry dehumidifier 100 so as to supply low dew point air to the low dew point chamber 20. Specifically, the control device 30 controls at least one of the rotation speed of the dehumidification rotor 101, the temperature of the regenerative heater 121, the air volume of the first fan 112, and the air volume of the second fan 124 based on a second dew point temperature 22 (also referred to as the second dew point temperature DP2) indicating the dew point temperature of the low dew point chamber 20 (room) and a first dew point temperature 11 (also referred to as the first dew point temperature DP1) indicating the dew point temperature of the dehumidified air to be supplied to the low dew point chamber 20.

[0022] For example, consider a case where the airflow rate of the first fan 112 is adjusted so that the second dew-point temperature 22 approaches a target dew-point temperature (e.g., −50° C. DP). If the first dew-point temperature 11 changes while control to adjust the airflow rate of the first fan 112 is being executed, the airflow rate of the first fan 112 may repeatedly increase and decrease, which may cause the control of the control device 30 to become unstable. For this reason, when adjusting the airflow rate of the first fan 112, it is preferable that the first dew-point temperature 11 be constant. Therefore, to keep the first dew-point temperature 11 constant, the control device 30 adjusts at least one of the airflow rate of the second fan 124, the temperature of the regeneration heater 121, and the rotation speed of the dehumidification rotor 101. This makes it possible to maintain the first dew-point temperature 11 constant even when the airflow rate of the first fan 112 is adjusted.

[0023] When adjusting the air volume of the first fan 112, the control device 30 generates and outputs a drive control signal (e.g., PWM signal) for the inverter 113 based on air volume setting information for the first fan 112. When adjusting the air volume of the second fan 124, the control device 30 generates and outputs a drive control signal (e.g., PWM signal) for the inverter 125 based on air volume setting information for the second fan 124. When adjusting the temperature of the regenerative heater 121, the control device 30 generates and outputs a control signal for the thyristor 122 based on temperature setting information for the regenerative heater 121. When adjusting the rotation speed of the dehumidifying rotor 101, the control device 30 generates and outputs a drive control signal (e.g., PWM signal) for the inverter 102 based on rotation speed setting information for the dehumidifying rotor 101.

[0024] 2. Specific examples of low dew point rooms FIG. 2 is an explanatory diagram showing a specific example of the low dew point chamber 20 according to the embodiment. FIG. 2(A) is a top view showing the second low dew point chamber 20B with its door closed, and FIG. 2(B) is a top view showing the second low dew point chamber 20B with its door open. As described above, the low dew point chamber 20 includes the first low dew point chamber 20A and the second low dew point chamber 20B. The low dew point chamber 20 includes a desiccant material 41 and an indoor fan 42. The desiccant material 41 is provided in the vent between the first low dew point chamber 20A and the second low dew point chamber 20B and absorbs moisture in the air. The desiccant material 41 is made of a material such as silica gel. The indoor fan 42 is provided outside the second low dew point chamber 20B, sandwiching the desiccant material 41. The indoor fan 42 is a blower that supplies air from the first low dew point chamber 20A into the second low dew point chamber 20B through the desiccant material 41. An example of the indoor fan 42 is an axial flow fan. The indoor fan 42 is also simply referred to as a "fan."

[0025] The indoor fan 42 is controlled to stop while the door of the second low dew point chamber 20B is closed and to operate while the door is open. There are various methods for driving the indoor fan 42. For example, a limit switch may be attached to the door, and the indoor fan 42 may be connected to the limit switch. In this case, when the door is opened, the contacts of the limit switch close, causing the indoor fan 42 to operate, and when the door is closed, the contacts of the limit switch open, causing the indoor fan 42 to stop. With this configuration, the indoor fan 42 can be started without going through the control device 30.

[0026] As another example, a configuration may be adopted in which a detection sensor that detects whether the door is open or closed is provided in the second low dew point chamber 20B, and the detection sensor controls the indoor fan 42. For example, if the signal output from the detection sensor when the door is open is a DC voltage required to drive the indoor fan 42, the indoor fan 42 operates based on that DC voltage. On the other hand, if the signal output from the detection sensor when the door is closed is a DC voltage of 0 V, the indoor fan 42 stops based on that DC voltage. With this configuration, control of the indoor fan 42 by the control device 30 is not necessary.

[0027] Consider the case where the door of the second low dew point chamber 20B is closed, i.e., the indoor fan 42 is stopped. In this case, the second low dew point chamber 20B (booth) maintains a positive pressure relative to the first low dew point chamber 20A (outside the booth), preventing moisture from entering from outside the booth. As a result, the air inside the booth is sent out toward the outside of the booth via the indoor fan 42, as shown in FIG. 2(A). In this case, the moisture adsorbed by the desiccant material 41 is desorbed.

[0028] Consider the case where the door of the second low dew point chamber 20B is open, i.e., the indoor fan 42 is operating. In this case, there is no pressure difference between the inside of the second low dew point chamber 20B (booth) and the first low dew point chamber 20A (outside the booth). However, as the indoor fan 42 operates, air into the second low dew point chamber 20B (booth) is supplied from the first low dew point chamber 20A (outside the booth) via the indoor fan 42, as shown in FIG. 2(B). At this time, the desiccant material 41 adsorbs moisture from the air outside the booth that is taken into the booth. However, over time, the desiccant material 41 becomes saturated, and its adsorption performance deteriorates. As a result, if the door of the second low dew point chamber 20B is left open for a certain period of time or longer, the absolute humidity of the air supplied from the first low dew point chamber 20A (outside the booth) to the second low dew point chamber 20B (booth) increases, and the dew point temperature inside the booth also increases.

[0029] Specifically, as shown in FIG. 3, when the door of the second low dew point chamber 20B is open, the absolute humidity of the supply air supplied from the first low dew point chamber 20A to the second low dew point chamber 20B via the indoor fan 42 remains constant until a certain time and then increases over time. The dew point temperature in the second low dew point chamber 20B also remains constant until a certain time and then increases over time. In the example shown in FIG. 3, the supply air absolute humidity and dew point temperature remain constant for approximately 10 minutes after the door of the second low dew point chamber 20B is opened, and then increase over time. In this case, the degree of increase in the supply air absolute humidity and dew point temperature increases as the wind speed of the indoor fan 42 increases. Because the door of the second low dew point chamber 20B is opened and closed only temporarily when a worker enters or exits the booth, the supply air absolute humidity and dew point temperature are maintained within a certain range.

[0030] According to this embodiment, when the door of the second low dew point chamber 20B is closed, the booth can maintain a positive pressure relative to the outside of the booth, thereby suppressing the inflow of moisture from outside the booth. On the other hand, when the door of the second low dew point chamber 20B is open for a certain period of time, the pressure difference between the inside and outside of the booth disappears, but the absolute humidity and dew point temperature of the supply air inside the booth are maintained within a certain range. Therefore, even if there is a booth within the low dew point chamber 20 that requires management at a lower dew point, the dew point temperature inside that booth can be stably controlled. Furthermore, because there is no need to dehumidify the air supplied to the first low dew point chamber 20A to the dew point temperature required for the second low dew point chamber 20B, the power consumption of the dehumidification system 1 can be reduced.

[0031] 3. Variations According to the embodiment described above, air into the booth is taken in from outside the booth via the indoor fan 42 and the desiccant material 41. However, this is not limiting. For example, the air supplied into the booth may be recirculated air. Even in this case, the dew point temperature inside the booth can be stably controlled. Below, we will explain in detail the low dew point chamber when the air supplied into the booth is recirculated air.

[0032] FIG. 4 is an explanatory diagram showing a specific example of the low dew point chamber 21 according to a modified example of the embodiment. FIG. 4(A) is a top view showing a state in which the door of the second low dew point chamber 21B is closed, and FIG. 4(B) is a top view showing a state in which the door of the second low dew point chamber 21B is open. The low dew point chamber 21 includes a first low dew point chamber 21A and a second low dew point chamber 21B. The second low dew point chamber 21B includes a desiccant material 41 and an indoor fan 42. The desiccant material 41 and the indoor fan 42 are disposed, for example, on the left side in a top view, i.e., on the side of the intake port connected to the first duct 131. The mounting method and configuration (e.g., materials) of the desiccant material 41 and the indoor fan 42 are the same as those described above. The indoor fan 42 is controlled to stop when the door of the second low dew point chamber 21B is closed and to operate when the door is open. The method of driving the indoor fan 42 is the same as that described above.

[0033] The low dew point chamber 21 further includes a return duct 44, a first automatic air volume regulator 45, and a second automatic air volume regulator 46. The vent includes a first vent and a second vent. One end of the return duct 44 is connected to the first vent, and the other end is connected to the second vent. As a result, air in the second low dew point chamber 21B (booth) that is drawn into the second vent of the return duct 44 passes through the return duct 44 and is exhausted from the first vent of the return duct 44. This allows the air in the second low dew point chamber 21B (booth) to be returned. The first vent is located on the left side in a top view, i.e., on the side of the intake port connected to the third duct 133. The second vent is located on the right side in a top view, i.e., on the side of the outlet connected to the first duct 131.

[0034] The first automatic air volume regulator 45 adjusts the amount of air taken into the return duct 44 from the second low dew point chamber 21B (booth). The first automatic air volume regulator 45 is attached to the second air vent inside the second low dew point chamber 21B. The first automatic air volume regulator 45 is, for example, a motor damper that automatically controls the opening and closing of a damper using a motor. The second automatic air volume regulator 46 adjusts the amount of air taken into the return duct 44 from the first low dew point chamber 21A (outside the booth). The second automatic air volume regulator 46 is attached to the third air vent between the return duct 44 and the first low dew point chamber 20A, outside the return duct 44. The second automatic air volume regulator 46 is, for example, a motor damper that automatically controls the opening and closing of a damper using a motor. Like the indoor fan 42, the first automatic air volume regulator 45 and the second automatic air volume regulator 46 may be controlled to open and close in response to the opening and closing of the door of the second low dew point chamber 21B.

[0035] Consider the case where the door of the second low dew point chamber 21B is closed, i.e., the indoor fan 42 is stopped. In this case, the first automatic air volume regulator 45 is controlled to open, and the second automatic air volume regulator 46 is controlled to close. This allows the second low dew point chamber 21B (booth) to maintain a positive pressure relative to the first low dew point chamber 21A (outside the booth), thereby suppressing the inflow of moisture from outside the booth. Therefore, the air inside the booth is circulated via the return duct 44, as shown in FIG. 4(A). Note that the second low dew point chamber 21B (booth) does not need to maintain a positive pressure relative to the first low dew point chamber 21A (outside the booth).

[0036] Consider the case where the door of the second low dew point chamber 21B is open, i.e., the indoor fan 42 is operating. In this case, the first automatic air volume regulator 45 is controlled to close, and the second automatic air volume regulator 46 is controlled to open. In this case, there is no pressure difference between the inside of the second low dew point chamber 21B (booth) and the first low dew point chamber 21A (outside the booth). However, the second automatic air volume regulator 46 opens and the indoor fan 42 operates, causing air from the first low dew point chamber 21A (outside the booth) to be drawn into the return duct 44 via the third air vent. The air drawn into the return duct 44 is then supplied to the second low dew point chamber 21B (booth) via the indoor fan 42 (see FIG. 4(B)). At this time, the desiccant material 41 adsorbs moisture from the air outside the booth that is drawn into the booth. However, over time, the desiccant material 41 becomes saturated, and its adsorption performance deteriorates. As a result, if the door of second low dew point chamber 21B is left open for a certain period of time or longer, the absolute humidity of the air supplied from first low dew point chamber 21A (outside the booth) to second low dew point chamber 21B (the booth) will increase, and the dew point temperature inside the booth will also increase. However, as described above, the door of second low dew point chamber 21B is only opened and closed temporarily when a worker enters or leaves the booth, so the absolute humidity of the air supplied and the dew point temperature are maintained within a certain range.

[0037] According to this modification of the present embodiment, when the door of the second low dew point chamber 21B is closed, the booth can maintain a positive pressure relative to the outside of the booth, thereby suppressing the inflow of moisture from outside the booth. On the other hand, when the door of the second low dew point chamber 21B is open for a certain period of time, the pressure difference between inside and outside the booth disappears, but the absolute humidity and dew point temperature of the supply air inside the booth are maintained within a certain range. Therefore, the same effects as those of the above-described embodiment can be obtained. [Explanation of symbols]

[0038] 1... Dehumidification system, 11... First dew point temperature, 20, 21... Low dew point room, 20A, 21A... First low dew point room, 20B, 21B... Second low dew point room, 22... Second dew point temperature, 30, 30A... Control device, 31... Door opening time calculation unit, 32... Threshold value determination unit, 33... Fan air volume adjustment control unit, 34... Door opening / closing frequency calculation unit, 35... Backup fan start control unit, 41... Desiccant material, 42... Indoor fan, 43... Door opening / closing detection sensor, 44... Return duct, 45... First automatic air volume regulator, 46... Second automatic air volume regulator, 51... Another Desiccant material, 52...another indoor fan, 100...dry dehumidifier, 101...dehumidification 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...third duct

Claims

1. A dehumidification system for controlling the dew point temperature of a low dew point room, The low dew point chamber includes a first low dew point chamber and a second low dew point chamber that is provided inside the first low dew point chamber, is maintained at a positive pressure relative to the first low dew point chamber, and has a dew point lower than that of the first low dew point chamber; The low dew point chamber is a desiccant material provided in a vent between the first low dew point chamber and the second low dew point chamber, which absorbs moisture in the air; a fan that is provided outside the second low dew point chamber and sandwiches the desiccant material therebetween, and that supplies air from the first low dew point chamber into the second low dew point chamber via the desiccant material; Equipped with The fan is controlled to stop while the door of the second low dew point chamber is closed and to operate while the door is open. A dehumidification system characterized by:

2. 10. The dehumidification system of claim 1, The ventilation opening includes a first ventilation opening and a second ventilation opening, The low dew point chamber further comprises: a return duct having one end connected to the first vent port and the other end connected to the second vent port; a first automatic air volume regulator attached to the second vent inside the second low dew point chamber and configured to regulate the amount of air taken into the return duct from the second low dew point chamber; a second automatic air volume regulator attached to a third vent between the return duct and the first low dew point chamber outside the return duct, the second automatic air volume regulator adjusting the amount of air taken into the return duct from the first low dew point chamber; Equipped with A dehumidification system characterized by:

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