Air conditioning system

Abstract

To provide an air-conditioning system capable of reliably stabilizing a dew-point temperature of outer air to be supplied to an object space from an outer conditioning machine even when the number of operating dust collecting machines is quite less and, at the same time, capable of executing stabilization and energy saving relating to operation of the outer conditioning machine.SOLUTION: An air-conditioning system 1 includes a return air motor damper 35 which can control the quantity of return air to be introduced to an outer conditioning machine 31 and an outer air motor damper 36 which can control the quantity of outer air to be introduced to the outer conditioning machine 31. In such a case that frequency relating to inverter control of the outer conditioning machine 31 gets to a lower limit frequency, operations of the motor dampers 35, 36 are so controlled that when the reduction of the operating number of dust collectors 201 is estimated, the opening of a return air duct 32 increases while the opening of an outer air supply duct 34 decreases, and on the other hand, when the increasing of the number of the operating dust collecting machines 201 is estimated, the opening of the return air duct 32 decreases while the opening of the outer air supply duct 34 increases.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an air conditioning system having an air conditioner that can take in outside air and process the taken-in outside air. [Background technology]

[0002] Conventionally, gas such as outside air whose temperature and humidity have been adjusted has been supplied to a specified target space (e.g., a space inside a building) in which multiple production devices are installed, in order to make the target space an appropriate environment for the production devices.

[0003] Air conditioning systems that supply temperature-adjusted gas to a target space are generally known to include an outdoor air conditioning unit that has a fan that takes in the gas and supplies it to the target space, a temperature control device that adjusts the temperature of the taken-in gas, and a humidistat that adjusts the humidity of the gas, and sends the gas from the outdoor air conditioning unit to the target space through a specified air supply path (see, for example, Patent Document 1, etc.). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2023-96038 Summary of the Invention [Problem to be solved by the invention]

[0005] In some cases, each production device is equipped with a dust collector, and each dust collector draws air into the target space and exhausts the gas to the outside. In this case, the amount of air drawn in, and therefore the pressure in the target space, increases or decreases as the number of operating dust collectors increases or decreases depending on the number of operating production devices. Therefore, it is possible to configure the outdoor air conditioner (especially the fan) to supply the required amount of gas to the target space based on the number of operating dust collectors by performing inverter control based on the pressure in the target space.

[0006] However, with this configuration, when the number of operating dust collectors is significantly low, the exhaust volume from the target space is also significantly low, significantly reducing the amount of gas (required amount) that needs to be supplied to the target space from the outdoor air-conditioning unit. Meanwhile, to stabilize the dew point temperature (supply air dew point temperature) of the gas supplied to the target space from the outdoor air-conditioning unit, a certain ratio (e.g., approximately 40%) of the outdoor air-conditioning unit's rated airflow (target amount) of gas needs to be supplied to the target space. Therefore, when the number of operating dust collectors is significantly low, the balance between the amount of gas (required amount) that needs to be supplied to the target space (target amount) to stabilize the supply air dew point temperature is disrupted, making it more likely that the outdoor air-conditioning unit's control will be disrupted. This disruption in the outdoor air-conditioning unit's control can result in an inappropriate supply air dew point temperature, making it difficult to maintain appropriate temperature and humidity levels within the target space.

[0007] To address this issue, it is possible to slightly open a door leading to the target space to increase the amount of exhaust from the target space, thereby creating a situation similar to that in which the number of operating dust collectors is increased. However, this would result in unnecessary exhaust, which could result in wasted energy related to the operation of the outdoor air-conditioning units.

[0008] The present invention has been made in consideration of the above circumstances, and its purpose is to provide an air conditioning system that can more reliably stabilize the dew point temperature of the gas supplied to the target space from the outdoor air conditioning unit, even when the number of operating dust collectors is significantly low, and that can stabilize the operation of the outdoor air conditioning unit and achieve energy savings. [Means for solving the problem]

[0009] The following describes each of the means suitable for achieving the above object, with specific effects of the corresponding means added as necessary.

[0010] Means 1. An air conditioning system equipped with an outdoor air conditioner that can take in outside air and supply it to a target space after processing the air, The outdoor air-conditioning unit is configured to be inverter-controlled based on the pressure in the target space, A return air duct that introduces return air from the target space to the outdoor air conditioning unit; an outside air supply path that introduces outside air into the return air path; A return air motor damper that is provided in the return air duct and that can adjust the amount of return air introduced into the outdoor air-conditioning unit by adjusting the opening degree of the return air duct; an outside air motor damper that is provided in the outside air supply passage and that can adjust the amount of outside air introduced into the outdoor air conditioning unit by adjusting the opening degree of the outside air supply passage; an operating unit number information acquisition means for acquiring information relating to the number of operating dust collectors capable of suctioning, each of which is arranged in the target space; a damper control means capable of controlling the operation of the return air motor damper and the outside air motor damper; an outdoor air-conditioning unit control means capable of controlling the operation of the outdoor air-conditioning unit; The outdoor air-conditioning unit control means controls the inverter of the outdoor air-conditioning unit based on the pressure in the target space when the frequency related to the inverter control of the outdoor air-conditioning unit exceeds a predetermined lower limit frequency, and stops the inverter control of the outdoor air-conditioning unit and operates the outdoor air-conditioning unit at the lower limit frequency when the frequency related to the inverter control of the outdoor air-conditioning unit becomes the lower limit frequency, After inverter control of the outdoor air-conditioning unit is stopped, the damper control means When it is estimated from the information acquired by the operating unit number information acquisition means that the number of operating dust collectors has decreased, the operation of the return air motor damper and the outside air motor damper is controlled so that the opening degree of the return air passage is increased while the opening degree of the outside air supply passage is decreased; When it is estimated from the information acquired by the operating unit number information acquisition means that the number of operating dust collectors has increased, the operation of the return air motor damper and the outside air motor damper is controlled so that the opening degree of the return air passage is decreased while the opening degree of the outside air supply passage is increased; Furthermore, the outdoor air conditioning unit control means is characterized in that, after inverter control of the outdoor air conditioning unit is stopped, when the return air path is fully closed and the outdoor air supply path is fully open, the outdoor air conditioning unit control means resumes inverter control of the outdoor air conditioning unit.

[0011] According to the above-mentioned means 1, the outdoor air-conditioning unit (especially the blower for sending gas to the target space) is always (when the number of operating dust collectors is equal to or greater than a predetermined number and the frequency related to the inverter control of the outdoor air-conditioning unit exceeds a predetermined lower limit frequency) inverter-controlled based on the pressure in the target space, but when the frequency related to the inverter control of the outdoor air-conditioning unit reaches the lower limit frequency, the inverter control of the outdoor air-conditioning unit (blower) is stopped by the outdoor air-conditioning unit control means, and the outdoor air-conditioning unit operates at the lower limit frequency. In other words, when the number of operating dust collectors decreases significantly, the inverter control of the outdoor air-conditioning unit is stopped, and the outdoor air-conditioning unit operates at the lower limit frequency.

[0012] After inverter control of the outdoor air-conditioning unit is stopped, the return air motor damper provided in the return air duct for introducing return air from the target space to the outdoor air-conditioning unit and the outside air motor damper provided in the outside air supply duct for introducing outside air into the return air duct are controlled as follows, based on information related to the number of operating dust collectors acquired by the operating unit number information acquisition means. That is, if it is estimated from the information acquired by the operating unit number information acquisition means that the number of operating dust collectors has decreased (compared to the number of operating dust collectors immediately before the information was acquired), the operation of both motor dampers is controlled so that the opening of the return air duct increases and the opening of the outside air supply duct decreases. On the other hand, if it is estimated from the information acquired by the operating unit number information acquisition means that the number of operating dust collectors has increased (compared to the number of operating dust collectors immediately before the information was acquired), the operation of both motor dampers is controlled so that the opening of the return air duct decreases and the opening of the outside air supply duct increases.

[0013] Therefore, when the number of operating dust collectors is relatively low, the amount of return air introduced from the target space to the outdoor air-conditioning unit corresponds to the number of operating dust collectors, thereby creating a situation equivalent to a situation in which the exhaust from the dust collectors is sufficiently high (a situation in which the number of operating dust collectors is sufficiently high). This allows the amount of gas (required amount) that needs to be supplied to the target space from the outdoor air-conditioning unit to be relatively large, even when the number of operating dust collectors is relatively low. Therefore, even if a certain ratio (e.g., about 40%) of the outdoor air-conditioning unit's rated airflow (target amount) of gas is sent to the target space to stabilize the supply air dew point temperature, the amount of gas (required amount) that needs to be supplied to the target space and the amount of gas to be supplied to the target space (target amount) can be appropriately maintained. As a result, the dew point temperature of the gas (supply air dew point temperature) supplied from the outdoor air-conditioning unit to the target space can be more reliably stabilized, and the outdoor air-conditioning unit can be operated stably. Furthermore, there is no need to exhaust unnecessary air from the target space to ensure stable operation of the outdoor air conditioning unit, and by controlling both motor dampers as described above, the required amount does not become excessively large, so energy waste related to the operation of the outdoor air conditioning unit can be prevented.

[0014] Means 2. An air conditioning system equipped with an outdoor air conditioner that can take in outside air and supply it to a target space after processing the air, The outdoor air-conditioning unit is configured to be inverter-controlled based on the pressure in the target space, A return air duct that introduces return air from the target space to the outdoor air conditioning unit; an outside air supply path that introduces outside air into the return air path; A return air motor damper that is provided in the return air duct and that can adjust the amount of return air introduced into the outdoor air-conditioning unit by adjusting the opening degree of the return air duct; an outside air motor damper that is provided in the outside air supply passage and that can adjust the amount of outside air introduced into the outdoor air conditioning unit by adjusting the opening degree of the outside air supply passage; an exhaust fan for sending exhaust air from a plurality of dust collectors capable of suctioning air to the outside of the target space through a predetermined exhaust path; an exhaust passage pressure sensor for measuring the pressure in the exhaust passage, which varies depending on the number of operating dust collectors; a damper control means capable of controlling the operation of the return air motor damper and the outside air motor damper; an outdoor air-conditioning unit control means capable of controlling the operation of the outdoor air-conditioning unit; The outdoor air-conditioning unit control means controls the inverter of the outdoor air-conditioning unit based on the pressure in the target space when the frequency related to the inverter control of the outdoor air-conditioning unit exceeds a predetermined lower limit frequency, and stops the inverter control of the outdoor air-conditioning unit and operates the outdoor air-conditioning unit at the lower limit frequency when the frequency related to the inverter control of the outdoor air-conditioning unit becomes the lower limit frequency, After inverter control of the outdoor air-conditioning unit is stopped, the damper control means When it is estimated that the pressure in the exhaust passage has decreased from the pressure measured by the exhaust passage pressure sensor, the operation of the return air motor damper and the outside air motor damper is controlled so that the opening of the return air passage increases while the opening of the outside air supply passage decreases; When it is estimated that the pressure in the exhaust passage has increased from the pressure measured by the exhaust passage pressure sensor, the operation of the return air motor damper and the outside air motor damper is controlled so that the opening of the return air passage is decreased while the opening of the outside air supply passage is increased; Furthermore, the outdoor air conditioning unit control means is characterized in that, after inverter control of the outdoor air conditioning unit is stopped, when the return air path is fully closed and the outdoor air supply path is fully open, the outdoor air conditioning unit control means resumes inverter control of the outdoor air conditioning unit.

[0015] Means 2 described above basically achieves the same effects as means 1 described above. That is, even when the number of operating dust collectors is considerably low, it is possible to more reliably stabilize the dew point temperature of the gas (supply air dew point temperature) supplied to the target space from the outdoor air-conditioning unit, and to achieve stabilization and energy conservation related to the operation of the outdoor air-conditioning unit.

[0016] Furthermore, according to the above-mentioned means 2, an exhaust passage pressure sensor capable of measuring the pressure in the exhaust passage, which varies depending on the number of operating dust collectors (operating status), is used to control both motor dampers, thereby reducing the costs associated with the installation and maintenance of the air conditioning system.

[0017] Means 3: The air conditioning system according to Means 2, further comprising exhaust fan control means for performing inverter control of the exhaust fan in accordance with the pressure measured by the exhaust passage pressure sensor.

[0018] If the number of operating dust collectors is high, the amount of air drawn by the dust collectors increases. Therefore, in order to properly exhaust air, a relatively low output from the exhaust fan is sufficient. On the other hand, if the number of operating dust collectors is low, the amount of air drawn by the dust collectors decreases. Therefore, in order to properly exhaust air, the output from the exhaust fan needs to be relatively high. Here, if the exhaust fan is operated at a fixed frequency to accommodate a small number of operating dust collectors, the output from the exhaust fan may become excessive depending on the number of operating dust collectors, which may result in wasted energy related to the operation of the exhaust fan.

[0019] In this regard, according to the above-mentioned means 3, inverter control of the exhaust fan is performed in accordance with the pressure measured by the exhaust path pressure sensor. Therefore, when the number of operating dust collectors is large and the pressure measured by the exhaust path pressure sensor is relatively high, the exhaust fan is operated at a relatively low frequency, whereas when the number of operating dust collectors is small and the pressure measured by the exhaust path pressure sensor is relatively low, the exhaust fan is operated at a relatively high frequency. This allows the exhaust fan to be operated appropriately in accordance with the number of operating dust collectors (operating status). As a result, energy waste related to the operation of the exhaust fan can be more reliably prevented, and ultimately the running costs of the entire air conditioning system can be further reduced.

[0020] The exhaust fan, return air motor damper, and outside air motor damper are each controlled based on the pressure measured by the exhaust passage pressure sensor. That is, the exhaust passage pressure sensor is commonly used to control the exhaust fan and both motor dampers. This simplifies the air conditioning system and more effectively reduces costs.

[0021] Means 4. A communication passage that connects the inside and outside of the exhaust passage; an exhaust-side motor damper that is provided in the communication passage and that can switch between a communication state and a non-communication state between the inside and outside of the exhaust passage by opening and closing the communication passage; The air conditioning system described in means 3 is characterized in that it comprises an exhaust side motor damper control means that can control the exhaust side motor damper to bring it into the communicating state when the frequency related to the inverter control of the exhaust fan reaches a predetermined lower limit frequency.

[0022] According to the above-mentioned means 4, when the number of operating dust collectors is considerably large and the frequency related to the inverter control of the exhaust fan reaches a predetermined lower limit frequency, the communication passage is opened, thereby establishing a communication state between the inside and outside of the exhaust path. This makes it possible to more reliably prevent damage or breakdown of the exhaust fan or exhaust path (exhaust duct, etc.) due to abnormal air pressure.

[0023] The technical features of the above means may be combined as appropriate. For example, the technical feature of the above means 1, which is provided with an exhaust passage pressure sensor or the like in addition to the operating unit number information acquisition means, may be combined with the technical feature of the above means 3 or 4. [Brief explanation of the drawings]

[0024] [Figure 1] FIG. 1 is a schematic diagram illustrating an example of an air conditioning system. [Figure 2] 4 is a flowchart showing the flow of an exhaust adjustment process. [Figure 3] FIG. 10 is a graph showing a rough relationship between the number of operating dust collectors and the pressure measured by an exhaust passage pressure sensor. [Figure 4]FIG. 10 is a graph showing a rough relationship between the pressure measured by the exhaust passage pressure sensor and the output frequency related to inverter control of the thermal exhaust fan. [Figure 5] 1A is a graph roughly showing the pressure and pressure changes at each part of the thermal exhaust fan and thermal exhaust duct when a large number of dust collectors are in operation, and FIG. 1B is a graph roughly showing the pressure and pressure changes at each part of the thermal exhaust fan and thermal exhaust duct when a small number of dust collectors are in operation. [Figure 6] 10 is a flowchart showing the flow of an operating unit number increase / decrease handling process. [Figure 7] FIG. 10 is a graph roughly showing the relationship between the pressure measured by the exhaust duct pressure sensor and the opening degree of the return air duct and the outside air supply duct. DETAILED DESCRIPTION OF THE INVENTION

[0025] An embodiment will be described below with reference to the drawings. Fig. 1 is a schematic diagram showing an example of an air conditioning system 1. The air conditioning system 1 has a function of adjusting the temperature and humidity of gas such as outside air, and then supplying the temperature-adjusted gas to predetermined target spaces S1, S2 (for example, a space inside a factory building), and a function of exhausting air from the target spaces S1, S2.

[0026] Each of the target spaces S1 and S2 is provided with a plurality of production equipment 200 (e.g., semiconductor production equipment), and each production equipment 200 can be switched between operating and stopped by, for example, an operator. Each production equipment 200 is equipped with a dust collector 201 capable of suctioning, and the operating state of the dust collector 201 is switched in accordance with the operation or stop of the production equipment 200. Therefore, if the production equipment 200 is operating, the dust collector 201 built in the production equipment 200 also operates, whereas if the production equipment 200 is stopped, the dust collector 201 built in the production equipment 200 also stops.

[0027] The air conditioning system 1 includes an exhaust system 2 that collectively exhausts air from both target spaces S1, S2, and a pair of outdoor air-conditioning systems 3 that correspond to each of the target spaces S1, S2.

[0028] First, a description will be given of the exhaust system 2. The exhaust system 2 includes an individual duct 21, a heat exhaust duct 22, a communication duct 23, a heat exhaust fan 24, an exhaust-side motor damper 25, an exhaust path pressure sensor 41, and a controller 42.

[0029] The exhaust path pressure sensor 41 and the controller 42 are components common to the outdoor air-conditioning unit system 3. In this embodiment, the thermal exhaust duct 22 constitutes the "exhaust path," and similarly, the communication duct 23 constitutes the "communication passage," and the thermal exhaust fan 24 constitutes the "exhaust fan." Furthermore, the controller 42, which is a component of the exhaust system 2, constitutes the "exhaust fan control means" and the "exhaust side motor damper control means." Furthermore, the exhaust path pressure sensor 41 also functions as the "operating unit number information acquisition means."

[0030] The individual ducts 21 correspond to one dust collector 201, and are provided in parallel in the same number as the dust collectors 201. The gas (heat exhaust air: HEA) sucked in by each dust collector 201 is introduced into each individual duct 21, and flows into the heat exhaust duct 22 through each individual duct 21.

[0031] The heat exhaust duct 22 is a duct for sending exhaust air from the multiple dust collectors 201 to the outside of the target spaces S1, S2. As described above, the exhaust air from each dust collector 201 flows into the heat exhaust duct 22 after passing through each individual duct 21. Therefore, the pressure inside the heat exhaust duct 22 increases or decreases depending on the number of operating dust collectors 201. In this embodiment, exhaust air from the target spaces S1, S2 is only discharged via the heat exhaust duct 22.

[0032] The communication duct 23 has a structure branching off from the heat exhaust duct 22, and is a duct for connecting the inside and outside of the heat exhaust duct 22 (more specifically, the inside of the heat exhaust duct 22 and the atmospheric pressure space outside the target spaces S1 and S2).

[0033] The thermal exhaust fan 24 is a fan for sending exhaust air from the multiple dust collectors 201 to the outside of the target spaces S1, S2 through the thermal exhaust duct 22. In this embodiment, multiple (two) thermal exhaust fans 24 are provided, and each thermal exhaust fan 24 is installed in a respective thermal exhaust duct 22.

[0034] Additionally, an exhaust fan inverter 24a is provided for each thermal exhaust fan 24 to control the rotation speed of the thermal exhaust fan 24 (more precisely, the rotation speed of the motor for rotating the thermal exhaust fan 24), and the thermal exhaust fan 24 is inverter-controlled by the exhaust fan inverter 24a. Therefore, increasing or decreasing the output frequency from the exhaust fan inverter 24a increases or decreases the rotation speed of the thermal exhaust fan 24, which in turn increases or decreases the output of the thermal exhaust fan 24 (the force that draws gas from the target spaces S1, S2 to outside the target spaces S1, S2 through the thermal exhaust duct 22). The exhaust fan inverter 24a is controlled by the controller 42.

[0035] The exhaust-side motor damper 25 is provided in the communication duct 23 and is configured to be switchable between at least two states: an open state and a closed state. By setting the exhaust-side motor damper 25 to the open state, the communication duct 23 is opened, and the inside and outside of the heat exhaust duct 22 are in a state of communication via the communication duct 23. On the other hand, by setting the exhaust-side motor damper 25 to the closed state, the communication duct 23 is closed, and the inside and outside of the heat exhaust duct 22 are in a state of non-communication.

[0036] The exhaust path pressure sensor 41 is provided in the heat exhaust duct 22 and measures the pressure inside the heat exhaust duct 22, which fluctuates depending on the number of operating production devices 200 and therefore the number of operating dust collectors 201. Therefore, the exhaust path pressure sensor 41 acquires the pressure inside the heat exhaust duct 22 as information related to the number of operating dust collectors 201. The exhaust path pressure sensor 41 is configured by, for example, a duct pressure sensor (barometric pressure sensor), and the pressure measured by the exhaust path pressure sensor 41 is output to the controller 42.

[0037] The controller 42 is configured, for example, by a microcontroller equipped with a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), etc. The controller 42, which is a component of the exhaust system 2, controls the thermal exhaust fan 24 via the exhaust fan inverter 24a and controls the opening and closing of the exhaust-side motor damper 25. The controller 42 is configured to be able to grasp the output frequency from the exhaust fan inverter 24a and the open / close state of the exhaust-side motor damper 25.

[0038] Furthermore, the controller 42 performs inverter control of the thermal exhaust fan 24 in accordance with the pressure measured by the exhaust path pressure sensor 41. That is, the controller 42 controls the output (number of rotations) of the thermal exhaust fan 24 by varying the output frequency from the exhaust fan inverter 24a in accordance with the pressure measured by the exhaust path pressure sensor 41.

[0039] In addition, when the frequency related to the inverter control of the thermal exhaust fan 24 (the output frequency of the exhaust fan inverter 24a) reaches a predetermined lower limit frequency, the controller 42 controls the exhaust side motor damper 25 to open the communication duct 23, thereby establishing a state in which the inside and outside of the thermal exhaust duct 22 are connected to each other.

[0040] Here, we will explain the control process (exhaust adjustment process) performed by the controller 42 on the thermal exhaust fan 24 and the exhaust-side motor damper 25. As shown in Figure 2 (note that in Figure 2 and other figures, the motor damper may be abbreviated as "MB" and the inverter as "INV"), in the exhaust adjustment process, first, in step S11, the controller 42 controls the inverter of the thermal exhaust fan 24 in accordance with the pressure measured by the exhaust path pressure sensor 41.

[0041] To explain the process of step S11 in more detail, it is first assumed that the pressure measured by the exhaust path pressure sensor 41 and the number of operating production apparatuses 200 and therefore dust collectors 201 are related to each other in that the pressure measured by the exhaust path pressure sensor 41 increases or decreases as the number of operating dust collectors 201 increases or decreases (see FIG. 3). Therefore, when the number of operating dust collectors 201 is large and the pressure measured by the exhaust path pressure sensor 41 is relatively high, i.e., when sufficient exhaust from the target spaces S1 and S2 can be achieved without increasing the output (rotation speed) of the thermal exhaust fan 24 significantly, the controller 42 sets the output frequency of the exhaust fan inverter 24a to a relatively low value, thereby operating the thermal exhaust fan 24 at a relatively low frequency (see FIG. 4). This allows sufficient exhaust from the target spaces S1 and S2 while keeping the output of the thermal exhaust fan 24 relatively low (see FIG. 5(a)).

[0042] 5(a) and 5(b) are pressure distribution diagrams for roughly showing the pressure and pressure changes in each part of the dust collector 201, the exhaust path pressure sensor 41, the heat exhaust fan 24, and the heat exhaust duct 22. In these diagrams, no consideration is given to bends and the like provided in the heat exhaust duct 22.

[0043] On the other hand, when the number of operating dust collectors 201 is relatively small and the pressure measured by the exhaust path pressure sensor 41 is relatively low, that is, when the output (rotation speed) of the thermal exhaust fan 24 needs to be increased to sufficiently exhaust air from the target spaces S1 and S2, the controller 42 sets the output frequency from the exhaust fan inverter 24a to a relatively high frequency, thereby operating the thermal exhaust fan 24 at a relatively high frequency (see FIG. 4). This results in a relatively high output from the thermal exhaust fan 24, and sufficient exhaust air is exhausted from the target spaces S1 and S2 (see FIG. 5(b)). Furthermore, in step S12 following step S11, the controller 42 determines whether the frequency related to the inverter control of the thermal exhaust fan 24 is a predetermined lower limit frequency. That is, the controller 42 determines whether the output frequency from the exhaust fan inverter 24a is the lower limit frequency. If the frequency related to the inverter control of the thermal exhaust fan 24 is the lower limit frequency (step S12: YES), then in step S13, the controller 42 opens the exhaust-side motor damper 25 to open the communication duct 23. On the other hand, if the frequency related to the inverter control of the thermal exhaust fan 24 is higher than the lower limit frequency (step S12: NO), the controller 42 keeps the exhaust-side motor damper 25 closed.

[0044] In addition, the controller 42 may have a function of automatically closing the exhaust side motor damper 25 if the frequency related to the inverter control of the thermal exhaust fan 24 exceeds a lower limit frequency after the exhaust side motor damper 25 is opened.

[0045] Next, we will explain the pair of outdoor air-conditioning systems 3. As shown in Fig. 1, one of the pair of outdoor air-conditioning systems 3 corresponds to the target space S1, and the other corresponds to the target space S2. Each outdoor air-conditioning system 3 has a similar configuration.

[0046] Each outdoor air-conditioning unit system 3 includes an outdoor air-conditioning unit 31, a return air duct 32, a supply air duct 33, an outdoor air supply duct 34, a return air motor damper 35, an outdoor air motor damper 36, and a room pressure sensor 37. Each outdoor air-conditioning unit system 3 also includes the above-mentioned exhaust path pressure sensor 41 and controller 42 as components common to the exhaust system 2. In this embodiment, the return air duct 32 constitutes the "return air path," and the outdoor air supply duct 34 constitutes the "outdoor air supply path." Furthermore, the controller 42, which is a component of the outdoor air-conditioning unit system 3, constitutes the "outdoor air-conditioning unit control means" and the "damper control means."

[0047] The outdoor air-conditioning unit 31 adjusts the temperature and humidity of gas (taken in outside air, return air from the target spaces S1, S2, or a mixture of these) and supplies the temperature-adjusted gas to the target spaces S1, S2. The outdoor air-conditioning unit 31 is equipped with a filter to remove dust contained in the gas, a temperature regulator that adjusts the temperature of the gas, a humidity controller that adjusts the humidity of the gas, and a blower (none of which are shown) that takes in the gas and supplies the gas to the target spaces S1, S2. The blower is composed of a fan that can increase or decrease the output (rotation speed).

[0048] The outdoor air-conditioning unit 31 also incorporates an outdoor air-conditioning unit inverter 31a for controlling the rotation speed of the blower, and the blower is inverter-controlled by this outdoor air-conditioning unit inverter 31a. Therefore, by increasing or decreasing the output frequency from the outdoor air-conditioning unit inverter 31a, the output (rotation speed) of the blower increases or decreases. The operation of the outdoor air-conditioning unit inverter 31a is controlled by a controller 42.

[0049] The return air duct 32 is a duct for introducing return air (RA) from the target spaces S1 and S2 to the outdoor air-conditioning unit 31.

[0050] The supply air duct 33 is a duct for supplying temperature-adjusted gas (SA (Supply Air)) from the outdoor air-conditioning unit 31 to the target spaces S1 and S2. A check damper 33a is provided in the supply air duct 33, and the check damper 33a prevents backflow of the gas supplied to the target spaces S1 and S2. The supply air duct 33 is also provided with a dew-point temperature sensor 33b, and the outdoor air-conditioning unit 31 is controlled by a controller 42 to adjust the temperature and humidity of the gas based on the dew-point temperature (supply air dew-point temperature) measured by the dew-point temperature sensor 33b.

[0051] The outside air supply duct 34 has a structure branching off from the return air duct 32, and is a duct for introducing outside air (OA (Outdoor Air)) into the return air duct 32.

[0052] The return air motor damper 35 is provided in the return air duct 32 and is a motor damper for adjusting the opening degree of the return air duct 32. By controlling the return air motor damper 35 and adjusting the opening degree of the return air duct 32, the amount of return air introduced into the outdoor air-conditioning unit 31 is adjusted. Note that control of the return air motor damper 35, i.e., adjustment of the opening degree of the return air duct 32, is performed by a controller 42.

[0053] The outside air motor damper 36 is provided in the outside air supply duct 34 and is a motor damper for adjusting the opening degree of the outside air supply duct 34. By controlling the outside air motor damper 36 and adjusting the opening degree of the outside air supply duct 34, the amount of outside air introduced into the outdoor air-conditioning unit 31 is adjusted. Note that the opening degree of the outside air supply duct 34 is adjusted by controlling the outside air motor damper 36 with the controller 42.

[0054] The room pressure sensor 37 is a sensor for measuring the pressure in the target spaces S1 and S2. The pressure measured by the room pressure sensor 37 is output to the controller .

[0055] The controller 42, which is a component of the outdoor air-conditioning unit system 2, controls the operation of the outdoor air-conditioning unit 31 (particularly the blower) via the outdoor air-conditioning unit inverter 31a, and controls the operation of the return air motor damper 35 and the outdoor air motor damper 36. The controller 42 is configured to be able to grasp the output frequency from the outdoor air-conditioning unit inverter 31a (i.e., the operating frequency of the blower) and the opening degrees of the return air motor damper 35 and the outdoor air motor damper 36.

[0056] The controller 42 controls both motor dampers 35, 36 so that the outside air supply duct 34 is always fully open while the return air duct 32 is always fully closed (that is, when the number of operating dust collectors 201 is equal to or greater than a predetermined number and the frequency related to the inverter control of the outdoor air-conditioning unit 31 is greater than a predetermined lower limit frequency). Therefore, when the number of operating dust collectors 201 is relatively large, return air is not introduced into the outdoor air-conditioning unit 31.

[0057] Furthermore, the controller 42 always (i.e., when the number of operating dust collectors 201 is equal to or greater than a predetermined number and the frequency related to inverter control of the outdoor air-conditioning unit 31 is greater than the lower limit frequency) performs inverter control of the outdoor air-conditioning unit 31 (particularly the blower) based on the pressure in the target spaces S1, S2 measured by the room pressure sensor 37. More specifically, the controller 42 controls the output (rotation speed) of the outdoor air-conditioning unit 31 (particularly the blower) by varying the output frequency from the outdoor air-conditioning unit inverter 31a based on the pressure measured by the room pressure sensor 37. Therefore, when the number of operating dust collectors 201 is relatively large, the amount of gas supplied from the outdoor air-conditioning unit 31 to the target spaces S1, S2 varies according to the pressure measured by the room pressure sensor 37.

[0058] The controller 42 basically controls the outdoor air conditioning unit 31 and both motor dampers 35, 36 as described above, but in order to more appropriately respond to a decrease in the number of operating dust collectors 201, it is configured to be able to perform the processing to respond to a decrease in the number of operating units described below.

[0059] 6, in the processing for dealing with a decrease in the number of operating units, first, in step S21, the controller 42 determines whether the frequency related to the inverter control of the outdoor air-conditioning unit 31 (the output frequency from the outdoor air-conditioning unit inverter 31a) is at the lower limit frequency. Here, if the frequency related to the inverter control of the outdoor air-conditioning unit 31 is higher than the lower limit frequency (step S21: NO), the controller 42 continues inverter control of the outdoor air-conditioning unit 31 with the outdoor air supply duct 34 fully open and the return air duct 32 fully closed, and controls the outdoor air-conditioning unit 31 based on the pressure measured by the room pressure sensor 37.

[0060] On the other hand, if the frequency related to the inverter control of the outdoor air-conditioning unit 31 is the lower limit frequency (step S21: YES), in step S22, the controller 42 stops the inverter control of the outdoor air-conditioning unit 31 and causes the outdoor air-conditioning unit 31 to continue operating at the lower limit frequency. In other words, the outdoor air-conditioning unit 31 is operated at a constant output so that the amount of gas required to stabilize the supply air dew point temperature (for example, about 40% of the rated air volume) is supplied to the target spaces S1 and S2.

[0061] After stopping the inverter control of the outdoor air-conditioning unit 31, in step S23, the controller 42 starts proportional control of the return air motor damper 35 and the outdoor air motor damper 36. This starts operation of the return air motor damper 35, which was in a stopped state.

[0062] In the following step S24, the controller 42 controls both the motor dampers 35, 36 based on the pressure measured by the exhaust passage pressure sensor 41, thereby adjusting the opening degrees of the return air duct 32 and the outside air supply duct 34.

[0063] More specifically, when the controller 42 estimates from the pressure measured by the exhaust path pressure sensor 41 that the pressure in the heat exhaust duct 22 has decreased (compared to the pressure measured immediately before the pressure was measured), it controls the operation of both motor dampers 35, 36 so as to increase the aperture of the return air duct 32 and decrease the aperture of the outside air supply duct 34 (see FIG. 7 ). Therefore, when the controller 42 estimates from the information acquired by the exhaust path pressure sensor 41 that the number of operating dust collectors 201 has decreased (compared to the number of operating dust collectors 201 immediately before the information was acquired), it controls the operation of both motor dampers 35, 36 so as to increase the aperture of the return air duct 32 and decrease the aperture of the outside air supply duct 34. By controlling both motor dampers 35, 36 in this manner, the amount of return air from the target spaces S1, S2 to the outdoor air-conditioning unit 31 increases in accordance with the amount of reduction in exhaust air by the dust collector 201. Therefore, the amount (required amount) of gas that needs to be supplied from the outdoor air-conditioning unit 31 to the target spaces S1 and S2 (which is determined by the exhaust volume by the dust collector 201 and the return air volume to the outdoor air-conditioning unit 31) remains relatively large (for example, at about 40% of the rated air volume of the outdoor air-conditioning unit 31).

[0064] On the other hand, when the controller 42 estimates from the pressure measured by the exhaust path pressure sensor 41 that the pressure in the heat exhaust duct 22 has increased (compared to the pressure measured immediately before measuring this pressure), it controls the operation of both motor dampers 35, 36 so that the aperture of the return air duct 32 decreases while the aperture of the outside air supply duct 34 increases. Therefore, when the controller 42 estimates from the information acquired by the exhaust path pressure sensor 41 that the number of operating dust collectors 201 has increased (compared to the number of operating dust collectors 201 immediately before acquiring this information), it controls the operation of both motor dampers 35, 36 so that the aperture of the return air duct 32 decreases while the aperture of the outside air supply duct 34 increases. By controlling both motor dampers 35, 36 in this manner, the amount of return air from the target spaces S1, S2 to the outdoor air-conditioning unit 31 is reduced in response to the increase in the amount of exhaust air from the dust collector 201. As a result, the amount (required amount) of gas that needs to be supplied from the outdoor air-conditioning unit 31 to the target spaces S1, S2 does not become excessively large, but is maintained at an approximately constant level.

[0065] The processes of steps S25 and S26 following step S24 are processes for determining whether or not the conditions for stopping the proportional control of both motor dampers 35, 36 and resuming inverter control of the outdoor air-conditioning unit 31 based on the pressure measured by the room pressure sensor 37 have been met. First, in step S25, the controller 42 determines whether or not the pressure measured by the exhaust passage pressure sensor 41 has increased (compared to the pressure measured immediately before the pressure was measured). In other words, the controller 42 determines whether or not an event has occurred that suggests an increase in the number of operating dust collectors 201. If the pressure measured by the exhaust passage pressure sensor 41 has not increased (step S25: NO), the process returns to step S24, and the controller 42 continues the proportional control of both motor dampers 35, 36.

[0066] On the other hand, if the pressure measured by the exhaust passage pressure sensor 41 has increased (step S25: YES), in step S26, the controller 42 determines whether the outside air supply duct 34 is fully open and the return air duct 32 is fully closed. That is, the controller 42 determines whether a situation has arisen in which return air from the target spaces S1, S2 to the outdoor air-conditioning unit 31 is not necessary (that is, a situation in which the number of operating dust collectors 201 is sufficiently large). If the outside air supply duct 34 is not fully open or the return air duct 32 is not fully closed (step S26: NO), the process returns to step S24, and the controller 42 continues proportional control of both motor dampers 35, 36.

[0067] On the other hand, if the outside air supply duct 34 is fully open and the return air duct 32 is fully closed (step S26: YES), in step S27 the controller 42 resumes inverter control of the outdoor air-conditioning unit 31 based on the pressure measured by the room pressure sensor 37, and in step S38 stops proportional control of both motor dampers 35, 36. As a result, the outside air supply duct 34 is fully opened, the return air duct 32 is fully closed, and the state returns to one in which gas according to the pressure measured by the room pressure sensor 37 is supplied from the outdoor air-conditioning unit 31 to the target spaces S1, S2.

[0068] As described above in detail, according to this embodiment, when the frequency related to the inverter control of the outdoor air-conditioning unit 31 reaches the lower limit frequency, the inverter control of the outdoor air-conditioning unit 31 (particularly the blower) is stopped, and the outdoor air-conditioning unit 31 operates at the lower limit frequency. In other words, when the number of operating dust collectors 201 decreases significantly, the inverter control of the outdoor air-conditioning unit 31 is stopped, and the outdoor air-conditioning unit 31 operates at the lower limit frequency.

[0069] After inverter control of the outdoor air-conditioning unit 31 is stopped, the return air motor damper 35 and the outside air motor damper 36 are controlled as follows based on the pressure measured by the exhaust path pressure sensor 41 (= information related to the number of operating dust collectors 201). That is, if it is estimated from the pressure measured by the exhaust path pressure sensor 41 that the pressure in the heat exhaust duct 22 has decreased (= the number of operating dust collectors 201 has decreased), the operation of both motor dampers 35, 36 is controlled so that the aperture of the return air duct 32 increases and the aperture of the outside air supply duct 34 decreases. On the other hand, if it is estimated from the pressure measured by the exhaust path pressure sensor 41 that the pressure in the heat exhaust duct 22 has increased (= the number of operating dust collectors 201 has increased), the operation of both motor dampers 35, 36 is controlled so that the aperture of the return air duct 32 decreases and the aperture of the outside air supply duct 34 increases.

[0070] Therefore, in a situation where the number of operating dust collectors 201 is considerably small, return air is introduced from the target spaces S1, S2 to the outdoor air-conditioning unit 31 in an amount corresponding to the number of operating dust collectors 201. As a result, a situation equivalent to a situation where the amount of exhaust air from the dust collectors 201 is sufficiently large (a situation where the number of operating dust collectors 201 is sufficiently large) can be created. As a result, even in a situation where the number of operating dust collectors 201 is considerably small, the amount (required amount) of gas that needs to be supplied from the outdoor air-conditioning unit 31 to the target spaces S1, S2 can be made sufficiently large. Therefore, even if an amount (target amount) of gas that is a certain ratio (for example, about 40%) of the rated airflow of the outdoor air-conditioning unit 31 is sent to the target spaces S1, S2 to stabilize the supply air dew point temperature, it is possible to appropriately maintain a balance between the amount (required amount) of gas that needs to be supplied to the target spaces S1, S2 and the amount (target amount) of gas to be supplied to the target spaces S1, S2. As a result, it is possible to more reliably stabilize the dew point temperature (supply air dew point temperature) of the gas supplied from the outdoor air-conditioning unit 31 to the target spaces S1, S2, and to stably operate the outdoor air-conditioning unit 31. Furthermore, there is no need to wastefully exhaust air from the target spaces S1, S2 for stable operation of the outdoor air-conditioning unit 31, and since the motor dampers 35, 36 are controlled as described above, the required amount does not become excessively large, so it is possible to prevent waste of energy related to the operation of the outdoor air-conditioning unit 31.

[0071] Additionally, in this embodiment, an exhaust path pressure sensor 41 capable of measuring the pressure inside the heat exhaust duct 22, which varies depending on the number of operating dust collectors 201 (operating status), is used to control both motor dampers 35, 36. Therefore, costs associated with the installation and maintenance of the air conditioning system 1 can be reduced.

[0072] Furthermore, in this embodiment, when the number of operating dust collectors 201 is large and the pressure measured by the exhaust path pressure sensor 41 is relatively high, the thermal exhaust fan 24 is operated at a relatively low frequency, whereas when the number of operating dust collectors 201 is small and the pressure measured by the exhaust path pressure sensor 41 is relatively low, the thermal exhaust fan 24 is operated at a relatively high frequency. Therefore, the thermal exhaust fan 24 can be operated appropriately depending on the number of operating dust collectors 201 (operating status). This makes it possible to more reliably prevent energy waste related to the operation of the thermal exhaust fan 24, and ultimately to further reduce the running costs of the entire air conditioning system 1.

[0073] Additionally, the thermal exhaust fan 24 and both motor dampers 35, 36 are each controlled based on the pressure measured by the exhaust path pressure sensor 41. That is, the exhaust path pressure sensor 41 is commonly used to control the thermal exhaust fan 24 and both motor dampers 35, 36. This allows for simplification of the air conditioning system 1 and more effective cost reduction.

[0074] Furthermore, when the number of operating dust collectors 201 becomes considerably large and the frequency related to the inverter control of the thermal exhaust fan 24 reaches the lower limit frequency, the communication duct 23 is opened, thereby establishing a state in which the inside and outside of the thermal exhaust duct 22 are in communication with each other. This makes it possible to more reliably prevent damage or malfunction of the thermal exhaust fan 24 or the thermal exhaust duct 22 due to abnormal air pressure.

[0075] The present invention is not limited to the above-described embodiment, and may be implemented as follows: Of course, other applications and modifications not exemplified below are also possible.

[0076] (a) In the above embodiment, the exhaust passage pressure sensor 41 also functions as an “operating unit number information acquisition means” that acquires information related to the number of operating dust collectors 201, but the “operating unit number information acquisition means” may be constituted by means other than the exhaust passage pressure sensor 41.

[0077] Therefore, for example, when the dust collector 201 is in operation, a predetermined operation signal indicating that the dust collector 201 is in operation is output from the dust collector 201 to the controller 42, and the controller 42 may be configured to acquire information related to the number of operating dust collectors 201 based on this operation signal. Alternatively, the controller 42 may be configured so that an operator or the like directly inputs information related to the number of operating dust collectors 201 to the controller 42. In these cases, the controller 42 constitutes the "operating number information acquisition means."

[0078] Furthermore, the "operating number information acquisition means" may be configured, for example, by a camera that photographs the dust collector 201 (production device 200) and an information processing device that determines whether the dust collector 201 (production device 200) is operating or stopped based on the image obtained by the camera, and acquires information related to the number of operating dust collectors 201 based on the determination result.

[0079] (b) In the above embodiment, the dust collector 201 is built into the production device 200, but it may be provided separately from the production device 200. Furthermore, the number of dust collectors 201 provided may differ from the number of production devices 200. For example, multiple dust collectors 201 may be provided for one production device.

[0080] Furthermore, the dust collector 201 may be provided independently of the production equipment 200. Therefore, it is not necessary to provide the production equipment 200 in the target spaces S1 and S2, and it is sufficient that at least the dust collector 201 is provided in the target spaces S1 and S2.

[0081] (c) In the above embodiment, a pair of outdoor air-conditioning systems 2 is provided corresponding to the two target spaces S1 and S2, but the number of outdoor air-conditioning systems 2 may be changed appropriately depending on the number of target spaces. Therefore, if there is one target space, only one outdoor air-conditioning system 2 needs to be provided. [Explanation of symbols]

[0082] 1...air conditioning system, 22...heat exhaust duct (exhaust path), 23...communicating duct (communicating path), 24...heat exhaust fan (exhaust fan), 25...exhaust side motor damper, 31...outdoor air conditioning unit, 32...return air duct (return air path), 34...outdoor air supply duct (outdoor air supply path), 35...return air motor damper, 36...outdoor air motor damper, 41...exhaust path pressure sensor (means for acquiring information on number of operating units), 42...controller (damper control means, outdoor air conditioning unit control means, exhaust fan control means, exhaust side motor damper control means).

Claims

1. An air conditioning system equipped with an outdoor air conditioner that can take in outside air, process the taken-in outside air, and then supply it to a target space, The outdoor air-conditioning unit is configured to be inverter-controlled based on the pressure in the target space, A return air duct that introduces return air from the target space to the outdoor air conditioning unit; an outside air supply path that introduces outside air into the return air path; A return air motor damper that is provided in the return air duct and that can adjust the amount of return air introduced into the outdoor air-conditioning unit by adjusting the opening degree of the return air duct; an outside air motor damper that is provided in the outside air supply passage and that can adjust the amount of outside air introduced into the outdoor air conditioning unit by adjusting the opening degree of the outside air supply passage; an operating unit number information acquisition means for acquiring information relating to the number of operating dust collectors capable of suctioning, each of which is arranged in the target space; a damper control means capable of controlling the operation of the return air motor damper and the outside air motor damper; an outdoor air-conditioning unit control means capable of controlling the operation of the outdoor air-conditioning unit; The outdoor air-conditioning unit control means controls the inverter of the outdoor air-conditioning unit based on the pressure in the target space when the frequency related to the inverter control of the outdoor air-conditioning unit exceeds a predetermined lower limit frequency, and stops the inverter control of the outdoor air-conditioning unit and operates the outdoor air-conditioning unit at the lower limit frequency when the frequency related to the inverter control of the outdoor air-conditioning unit becomes the lower limit frequency, After inverter control of the outdoor air-conditioning unit is stopped, the damper control means When it is estimated from the information acquired by the operating unit number information acquisition means that the number of operating dust collectors has decreased, the operation of the return air motor damper and the outside air motor damper is controlled so that the opening degree of the return air passage is increased while the opening degree of the outside air supply passage is decreased; When it is estimated from the information acquired by the operating unit number information acquisition means that the number of operating dust collectors has increased, the operation of the return air motor damper and the outside air motor damper is controlled so that the opening degree of the return air passage is decreased while the opening degree of the outside air supply passage is increased; Furthermore, the outdoor air conditioning unit control means is characterized in that, after inverter control of the outdoor air conditioning unit is stopped, when the return air path is fully closed and the outdoor air supply path is fully open, the outdoor air conditioning unit control means resumes inverter control of the outdoor air conditioning unit.

2. An air conditioning system equipped with an outdoor air conditioner that can take in outside air, process the taken-in outside air, and then supply it to a target space, The outdoor air-conditioning unit is configured to be inverter-controlled based on the pressure in the target space, A return air duct that introduces return air from the target space to the outdoor air conditioning unit; an outside air supply path that introduces outside air into the return air path; A return air motor damper that is provided in the return air duct and that can adjust the amount of return air introduced into the outdoor air-conditioning unit by adjusting the opening degree of the return air duct; an outside air motor damper that is provided in the outside air supply passage and that can adjust the amount of outside air introduced into the outdoor air conditioning unit by adjusting the opening degree of the outside air supply passage; an exhaust fan for sending exhaust air from a plurality of dust collectors capable of suctioning air to the outside of the target space through a predetermined exhaust path; an exhaust passage pressure sensor for measuring the pressure in the exhaust passage, which varies depending on the number of operating dust collectors; a damper control means capable of controlling the operation of the return air motor damper and the outside air motor damper; an outdoor air-conditioning unit control means capable of controlling the operation of the outdoor air-conditioning unit; The outdoor air-conditioning unit control means controls the inverter of the outdoor air-conditioning unit based on the pressure in the target space when the frequency related to the inverter control of the outdoor air-conditioning unit exceeds a predetermined lower limit frequency, and stops the inverter control of the outdoor air-conditioning unit and operates the outdoor air-conditioning unit at the lower limit frequency when the frequency related to the inverter control of the outdoor air-conditioning unit becomes the lower limit frequency, After inverter control of the outdoor air-conditioning unit is stopped, the damper control means When it is estimated that the pressure in the exhaust passage has decreased from the pressure measured by the exhaust passage pressure sensor, the operation of the return air motor damper and the outside air motor damper is controlled so that the opening of the return air passage increases while the opening of the outside air supply passage decreases; When it is estimated that the pressure in the exhaust passage has increased from the pressure measured by the exhaust passage pressure sensor, the operation of the return air motor damper and the outside air motor damper is controlled so that the opening of the return air passage is decreased while the opening of the outside air supply passage is increased; Furthermore, the outdoor air conditioning unit control means is characterized in that, after inverter control of the outdoor air conditioning unit is stopped, when the return air path is fully closed and the outdoor air supply path is fully open, the outdoor air conditioning unit control means resumes inverter control of the outdoor air conditioning unit.

3. 3. The air conditioning system according to claim 2, further comprising an exhaust fan control means for controlling an inverter of the exhaust fan in accordance with the pressure measured by the exhaust passage pressure sensor.

4. a communication passage that communicates the inside and outside of the exhaust passage; an exhaust-side motor damper that is provided in the communication passage and that can switch between a communication state and a non-communication state between the inside and outside of the exhaust passage by opening and closing the communication passage; 4. The air conditioning system according to claim 3, further comprising an exhaust side motor damper control means for controlling the exhaust side motor damper to bring the exhaust fan into the communicating state when the frequency related to the inverter control of the exhaust fan reaches a predetermined lower limit frequency.

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