Air conditioning system and ventilation control method

Abstract

In an air conditioning system including a ventilation device, in order to be able to perform ventilation of a required minimum time and amount in a range in which a carbon dioxide concentration of a space that is a ventilation target does not exceed a given value, the air conditioning system includes a ventilation device and a control section that controls the ventilation device, the control section acquires a carbon dioxide concentration of a space that is a ventilation target of the ventilation device, and adjusts a ventilation amount of the ventilation device based on a current value of the carbon dioxide concentration and a temporal change in the carbon dioxide concentration.

Description

Technical Field

[0001] This invention relates to air conditioning systems and ventilation control methods. Background Technology

[0002] There are air conditioning systems that control air conditioning units and ventilation units to adjust the indoor ventilation status. For example, a known technique is to detect indoor carbon dioxide levels, and if the carbon dioxide concentration is above a threshold concentration, to set a priority ventilation mode, stop the air conditioner 1, and allow the ventilation unit 3 to operate (see, for example, Patent Document 1).

[0003] <Prior art documents>

[0004] <Patent Documents>

[0005] Patent Document 1: Japanese Patent Application Publication No. 2000-088320 Summary of the Invention

[0006] <Problem to be solved by this invention>

[0007] In air conditioning systems that include ventilation devices, there is a requirement to perform ventilation for the minimum amount of time required, in order to save energy, while ensuring that the carbon dioxide concentration in the space to be ventilated does not exceed a given value.

[0008] However, in existing technologies, such as those shown in Patent Document 1, there is a problem that sufficient energy saving cannot be achieved because the ventilation device starts operating or the ventilation volume is increased when the carbon dioxide concentration exceeds a threshold.

[0009] This invention enables air exchange of the required minimum time and amount to be performed in an air conditioning system including a ventilation device, provided that the carbon dioxide concentration in the space to be ventilated does not exceed a given value.

[0010] <Methods for solving problems>

[0011] The first aspect of the present invention relates to an air conditioning system that includes a ventilation device and a control unit for controlling the ventilation device. The control unit obtains the carbon dioxide concentration of the space to which the ventilation device is to be ventilated, and adjusts the ventilation rate of the ventilation device based on the current value of the carbon dioxide concentration and the time change of the carbon dioxide concentration.

[0012] According to the first aspect of the present invention, in an air conditioning system including a ventilation device, ventilation can be performed for a minimum required time and amount within a range where the carbon dioxide concentration in the space to be ventilated does not exceed a given value.

[0013] In the second aspect of the present invention, in the air conditioning system described in the first aspect, the control unit uses the current value of the carbon dioxide concentration, a given value for the given carbon dioxide concentration, and the time variation of the carbon dioxide concentration to adjust the ventilation rate of the ventilation device. Thus, the air conditioning system can utilize information about the time variation of the carbon dioxide concentration to suppress the situation where the carbon dioxide concentration in the space to be ventilated reaches the given value, and to suppress the ventilation rate.

[0014] In the third aspect of the present invention, in the air conditioning system described in the first aspect, the control unit uses the difference between the current value of the carbon dioxide concentration and the given value of the carbon dioxide concentration, as well as the time variation of the carbon dioxide concentration, to adjust the ventilation rate of the ventilation device. Therefore, the air conditioning system can utilize the information of the difference between the current value of the carbon dioxide concentration and the given value of the carbon dioxide concentration to suppress the situation where the carbon dioxide concentration in the space to be ventilated reaches the given value, and to suppress the ventilation rate.

[0015] In the fourth aspect of the present invention, in the air conditioning system described in the first aspect, the control unit,

[0016] Based on the current value of the carbon dioxide concentration and the time change of the carbon dioxide concentration, the system calculates the arrival time before the carbon dioxide concentration reaches a given value, and adjusts the ventilation rate of the ventilation device based on the arrival time. Thus, the air conditioning system can use the information of the arrival time before the carbon dioxide concentration reaches the given value to suppress the occurrence of a given carbon dioxide concentration in the space to be ventilated, and suppress the ventilation rate.

[0017] In the fifth aspect of the present invention, in the air conditioning system described in the first or fourth aspect, the control unit increases the ventilation rate of the ventilation device by a first increment when the current value of the carbon dioxide concentration is less than a predetermined first given value of the carbon dioxide concentration and the arrival time before the carbon dioxide concentration reaches the first given value is within a first time.

[0018] In the sixth aspect of the present invention, in the air conditioning system described in the fifth aspect, when the arrival time is within a second time shorter than the first time, the control unit increases the ventilation rate of the ventilation device by a second increase greater than the first increase. Therefore, even when the carbon dioxide concentration rises rapidly, the air conditioning system can ensure that the carbon dioxide concentration does not exceed a first given value and suppress the ventilation rate.

[0019] In the seventh aspect of the present invention, in the air conditioning system described in the first or fourth aspect, the control unit reduces the sensor value of the ventilation device by a first reduction when the current value of the carbon dioxide concentration is greater than a predetermined second given value of the carbon dioxide concentration, and the time before the carbon dioxide concentration reaches the second given value is within a third time. Therefore, the air conditioning system can suppress the ventilation rate when the carbon dioxide concentration decreases rapidly.

[0020] In the air conditioning system described in the seventh aspect of the present invention, the control unit reduces the ventilation volume of the ventilation device or stops the operation of the ventilation device by a second reduction that is larger than the first reduction when the arrival time is within a fourth time shorter than the third time.

[0021] In the ninth aspect of the present invention, in the air conditioning system of any one of the first to eighth aspects, the control unit stops the operation of the ventilation device when the current value of the carbon dioxide concentration is below a predetermined given threshold value of the carbon dioxide concentration.

[0022] In the tenth aspect of the present invention, in the air conditioning system of any one of the first to ninth aspects, the air conditioning system includes a plurality of ventilation devices, and the control unit adjusts the ventilation volume of the plurality of ventilation devices based on the current value of the carbon dioxide concentration and the time change of the carbon dioxide concentration.

[0023] In the 11th aspect of the present invention, in the air conditioning system of any one of the 1st to 10th aspects, the time interval for the control unit to determine the air exchange rate is longer than the time interval for measuring the carbon dioxide concentration.

[0024] In the 12th aspect of the present invention, in the air conditioning system described in any one of aspects 1 to 11, the control unit smooths the acquired carbon dioxide concentration to calculate the time variation of the carbon dioxide concentration. As a result, the air conditioning system can reduce the adverse effects caused by fluctuations in the carbon dioxide concentration data.

[0025] In the 13th aspect of the present invention, in the air conditioning system of any one of the 1st to 12th aspects, the air conditioning system includes the ventilation device and a communication device capable of communicating with the ventilation device, the communication device having the control unit.

[0026] The ventilation control method according to the 14th aspect of the present invention is used in an air conditioning system including a ventilation device and a control unit that controls the ventilation device. The control unit obtains the carbon dioxide concentration of the space to which the ventilation device is to be ventilated, and adjusts the ventilation rate of the ventilation device based on the current value of the carbon dioxide concentration and the time change of the carbon dioxide concentration.

[0027] The procedure according to the 15th aspect of the present invention, in an air conditioning system including a ventilation device and a control unit that controls the ventilation device, causes the control unit to obtain the carbon dioxide concentration of the space to be ventilated by the ventilation device, and adjusts the ventilation rate of the ventilation device based on the current value of the carbon dioxide concentration and the time change of the carbon dioxide concentration. Attached Figure Description

[0028] Figure 1 Figure (1) shows a structural example of the air conditioning system involved in this embodiment.

[0029] Figure 2 This is a diagram used to explain the outline of the processing involved in this embodiment.

[0030] Figure 3 Figure (2) shows a structural example of the air conditioning system involved in this embodiment.

[0031] Figure 4 Figure (3) shows a structural example of the air conditioning system involved in this embodiment.

[0032] Figure 5 This is a diagram illustrating an example of the hardware structure of the computer involved in this embodiment.

[0033] Figure 6 This is a flowchart illustrating an example of the ventilation volume adjustment process involved in this embodiment.

[0034] Figure 7A Figure (1) is used to illustrate the process for determining the ventilation volume involved in Example 1.

[0035] Figure 7B Figure (2) is used to illustrate the process for determining the ventilation volume involved in Example 1.

[0036] Figure 7C Figure (3) is used to illustrate the process for determining the ventilation volume involved in Example 1.

[0037] Figure 8A Figure (1) is used to illustrate the process for determining the ventilation volume involved in Example 2.

[0038] Figure 8B Figure (2) is used to illustrate the process for determining the ventilation volume involved in Example 2.

[0039] Figure 9 Figure (3) is used to illustrate the process for determining the ventilation volume involved in Example 2.

[0040] Figure 10Figure (1) is used to illustrate the process for determining the ventilation volume involved in Example 3.

[0041] Figure 11A Figure (2) is used to illustrate the process for determining the ventilation volume involved in Example 3.

[0042] Figure 11B Figure (3) is used to illustrate the process for determining the ventilation volume involved in Example 3.

[0043] Figure 11C Figure (4) is used to illustrate the process for determining the ventilation volume involved in Example 3.

[0044] Figure 12 This is a flowchart (1) illustrating an example of the ventilation volume adjustment process involved in Example 4.

[0045] Figure 13 This is a diagram used to illustrate the adjustment process of ventilation volume involved in Example 4.

[0046] Figure 14 This is a flowchart (2) illustrating an example of the ventilation volume adjustment process involved in Example 4.

[0047] Figure 15 This is a diagram used to illustrate the effect of the air conditioning system involved in this embodiment. Detailed Implementation

[0048] Hereinafter, embodiments of the present invention (this embodiment) will be described with reference to the accompanying drawings. Furthermore, in this specification and the accompanying drawings, constituent elements having substantially the same functional structure are labeled with the same reference numerals, and repeated descriptions are omitted.

[0049] <Structure of Air Conditioning System>

[0050] Figure 1 Figure (1) shows a structural example of the air conditioning system according to this embodiment. Figure 1 In the example, the air conditioning system 1 includes a communication device 10, ventilation devices 11a, 11b, ..., a CO2 sensor 12, and a management server 100 that can communicate with the communication device 10 via a communication network N. Furthermore, the air conditioning system 1 may also include air conditioners 13a, 13b, ..., and a management terminal 20. In the following description, "ventilation device 11" is used to refer to any one of the ventilation devices 11a, 11b, ... and "air conditioner 13" is used to refer to any one of the air conditioners 13a, 13b, ...

[0051] The ventilation device 11 is a ventilation device that takes the target area 2 as the ventilation target. Figure 1 The number of ventilation devices 11 shown is one example, but the number of ventilation devices 11 can also be more than one. In addition, the target area 2 is an example of a space that serves as the ventilation target of the ventilation device 11.

[0052] CO2 sensor 12 is a sensor for measuring the carbon dioxide concentration (hereinafter referred to as CO2 concentration) in the target area 2. CO2 sensor 12 can be installed in the target area 2, or in the space through which air drawn in from the target area 2 passes. Furthermore, CO2 sensor 12 can be included in the ventilation device 11, or in the air conditioner 13.

[0053] Air conditioner 13 is an air conditioning unit that targets area 2 for air conditioning. Additionally, Figure 1 The number of air conditioners 13 shown is an example, but the number of air conditioners 13 can also be more than one. Furthermore, in this embodiment, the air conditioners 13 are optional and not mandatory.

[0054] The communication device 10 is an information processing device with a computer structure, and is communicatively connected to, for example, the ventilation device 11, the CO2 sensor 12, and the air conditioner 13. Furthermore, the communication device 10 can communicate with the management server 100 or the management terminal 20 via a communication network N such as the Internet or a LAN (Local Area Network). For example, the communication device 10 acquires measurement data of the CO2 concentration in the target area 2 measured by the CO2 sensor 12, operation data of the ventilation device 11, and operation data of the air conditioner, and sends them to the management server 100. In addition, the communication device 10 forwards control data received from the management server 100 for the ventilation device 11 and the air conditioner 13 to the ventilation device 11 and the air conditioner 13.

[0055] Management server 100 is an information processing device with a computer structure, or a system comprising multiple computers. Figure 1 In the example, the management server 100 has a communication unit 101, a control unit 102, and a storage unit 110, etc.

[0056] The communication unit 101 connects the management server 100 to the communication network N and performs communication processing to communicate with the communication device 10 and the manager terminal 20, etc.

[0057] The control unit 102 is a processor, such as a CPU (Central Processing Unit), that is present in the management server 100. The control unit 102 obtains the CO2 concentration of the target area 2 by executing a program stored in a storage medium such as the storage unit 110, and performs an adjustment process for adjusting the ventilation volume of the ventilation device 11 based on the current value of the CO2 concentration and the time change of the CO2 concentration.

[0058] The storage unit 110 is implemented by storage devices or the like provided by the management server 100, including various types of data, information, and programs, such as CO2 concentration data (CO2 concentration data 111) obtained by the storage control unit 102 and various setting information 112. Alternatively, the storage unit 110 may also be implemented by other servers or cloud storage that can communicate with the management server 100 via a communication network N.

[0059] The management terminal 20 is an information processing device, such as a PC, tablet, or smartphone, used by an administrator 21 or similar entity to manage the air conditioning system 1. For example, the administrator 21 can use the management terminal 20 to log into the management server 100 to set or change the configuration information 112. However, in this embodiment, the management terminal 20 is optional and not mandatory.

[0060] <Summary of the Process>

[0061] Figure 2 This is a diagram used to explain the overview of the process involved in this embodiment. In this diagram, an example of the time change of CO2 concentration 201 in target region 2 is shown, with the horizontal axis representing time and the left vertical axis representing CO2 concentration [ppm]. Furthermore, in this diagram, the horizontal axis represents time and the right vertical axis represents ventilation rate [m³ / s]. 3 / h] This shows an example of the control unit 102 controlling the ventilation volume 205 of the ventilation device 11.

[0062] CO2 concentration (carbon dioxide concentration) is shown as 1m 3 Data on the proportion of carbon dioxide contained. The outdoor CO2 concentration is around 400 ppm, and the benchmark for indoor carbon dioxide concentration is set, for example, below 1000 ppm.

[0063] When the ventilation device 11 stops, the CO2 concentration in the target area 2 decreases due to human respiration, for example, as... Figure 2 The CO2 concentration 201 increases over time, from t0 to t1. Furthermore, the temporal variation of this CO2 concentration 201 varies depending on the number of people in the target area 2.

[0064] Therefore, the control unit 102 adjusts the ventilation rate of the ventilation device 11 based, for example, the current value 202 of the CO2 concentration 201 in the target region 2 and the slope (time change) 203 of the CO2 concentration 201, so that the CO2 concentration 201 converges from a first given value (e.g., 1000 ppm) to a second given value (e.g., 800 ppm) within a range 206.

[0065] For example, control unit 102 in Figure 2 At time t1, based on the current value 202 of CO2 concentration 201 and the slope 203 of CO2 concentration 201, when CO2 concentration 201 is about to exceed the first given value, the operation of the ventilation device 11 begins.

[0066] Preferably, the control unit 102 controls the ventilation rate of the ventilation device 11 in stages based on the current value 202 of the CO2 concentration 201 and the slope 203 of the CO2 concentration 201. For example, if the CO2 concentration 201 reaches the first given value in a shorter time, the control unit 102 sets the ventilation rate of the ventilation device 11 to be larger.

[0067] Furthermore, even with the same ventilation rate, the CO2 concentration 201 in target area 2 varies depending on the number of people located in target area 2. For example, in Figure 2 Around time t2, the number of people in object region 2 decreases, and the CO2 concentration 201 in object region 2 decreases. In this case, control unit 102, for example, in... Figure 2 At time t2, based on the current value of CO2 concentration 201 and the slope of CO2 concentration 201, when the CO2 concentration 201 is about to fall below the second given value, the ventilation rate of the ventilation device 11 is reduced. Figure 2 In the example, the control unit 102 reduces the ventilation volume of the ventilation device 11 by one level at time t2.

[0068] Similarly, control unit 102, for example, in Figure 2 At time t3, based on the current value of CO2 concentration 201 and the slope of CO2 concentration 201, when CO2 concentration 201 is about to exceed the first given value, the ventilation rate of the ventilation device 11 is increased again. Figure 2 In the example, the control unit 102 increases the ventilation rate of the ventilation device 11 by one level at time t3.

[0069] Similarly, control unit 102, for example, in Figure 2 At time t4, based on the current value of CO2 concentration 201 and the slope of CO2 concentration 201, when the CO2 concentration 201 is about to fall below the second given value, the ventilation rate of the ventilation device 11 is reduced again. Figure 2 In the example, the control unit 102 reduces the ventilation volume of the ventilation device 11 by one level at time t4.

[0070] Furthermore, the control unit 102, for example, in Figure 2 At time t5, based on the current value of CO2 concentration 201 and the slope of CO2 concentration 201, when CO2 concentration 201 is lower than the second given value and continues to decrease, the operation of the ventilation device 11 is stopped.

[0071] For example, in the prior art as shown in Patent Document 1, the ventilation device starts operating when the CO2 concentration exceeds a threshold. However, in this method, for example, even when the CO2 concentration rises slowly and does not reach 1000 ppm, the ventilation device starts operating when the CO2 concentration exceeds the threshold.

[0072] On the other hand, in this embodiment, based on the current value 202 of CO2 concentration 201 and the slope 203 of CO2 concentration 201, the operation of the ventilation device 11 is started when the CO2 concentration 201 is about to exceed 1000 ppm (an example of the first given value). Therefore, according to the air conditioning system 1 of this embodiment, unnecessary operation of the ventilation device 11 can be suppressed. For example, the air conditioning system 1 can delay the start time of operation of the ventilation device 11 to a limit.

[0073] Furthermore, by utilizing any one of the following information—the time variation of CO2 concentration, the difference between the given value and the CO2 concentration, or the arrival time of CO2 concentration before reaching the given value—the air conditioning system 1 can suppress the occurrence of CO2 concentration reaching the given concentration and suppress the ventilation rate. Moreover, by varying the amount of ventilation rate increase based on the arrival time of CO2 concentration reaching the given concentration, the air conditioning system 1 can suppress the occurrence of CO2 concentration reaching the given concentration and reduce the ventilation rate.

[0074] Furthermore, in the prior art, when the CO2 concentration exceeds a threshold, the ventilation device 11 continues to operate even if the CO2 concentration tends to decrease. On the other hand, in this embodiment, even if the CO2 concentration exceeds 800 ppm (an example of the second given value), the ventilation rate of the ventilation device 11 is reduced or the operation of the ventilation device 11 is stopped when the CO2 concentration tends to decrease. Therefore, the air conditioning system 1 according to this embodiment can further suppress unnecessary operation of the ventilation device 11.

[0075] As described above, according to the air conditioning system 1 of this embodiment, the carbon dioxide concentration in the space (object area 2) to which the air exchange is to be performed does not exceed a given value, and the required minimum time and amount of air exchange can be performed.

[0076] in addition, Figure 1 The structure of the air conditioning system 1 shown is an example. For example, in Figure 1In the middle, the management server 100 has a communication unit 101, a control unit 102, and a storage unit 110, etc. Figure 3 As shown, it can also be provided by the communication device 10. Thus, the air conditioning system 1 can adjust the ventilation rate of the ventilation device 11 based on the current value of the CO2 concentration 201 of the object area 2 and the time change of the CO2 concentration 201, without relying on the management server 100, so that the CO2 concentration 201 converges within a given value range 206.

[0077] In addition, the communication unit 101, control unit 102, and storage unit 110, etc. Figure 4 As shown, it can also be provided by the ventilation device 11. Thus, the air conditioning system 1 can adjust the ventilation rate of the ventilation device 11 based on the current value of the CO2 concentration 201 of the target area 2 and the time change of the CO2 concentration 201, without relying on the communication device 10, so that the CO2 concentration 201 converges within a given value range 206.

[0078] Furthermore, the communication unit 101, control unit 102, and storage unit 110 can also be distributed among the management server 100, communication device 10, or ventilation device 11. In short, the communication unit 101, control unit 102, and storage unit 110 can be present in any device within the air conditioning system 1, as long as the air conditioning system 1 has them.

[0079] <Hardware Structure>

[0080] Management server 100, communication device 10, and administrator terminal 20, etc., for example, have Figure 5 The hardware structure of the computer 500 is shown. Additionally, the management server 100 may be composed of multiple computers 500. Furthermore, the ventilation device 11 may also have the hardware structure of a computer 500.

[0081] Figure 5 This diagram illustrates an example of the hardware structure of a computer according to this embodiment. The computer 500 includes, for example, a control unit 102, a memory 501, a storage device 502, a communication I / F (Interface) 503, an output device 504, an input device 505, a driver device 506, and so on.

[0082] The control unit 102 implements various functions, such as a CPU, by executing a given program stored in a storage medium such as a storage device 502 or a memory 501. In addition to a CPU, the control unit 102 may also include processors such as a GPU (Graphics Processing Unit) or a DSP (Digital Signal Processor).

[0083] The memory 501 includes, for example, volatile memory such as RAM (Random Access Memory) serving as the working area of ​​the control unit 102, and non-volatile memory such as ROM (Read Only Memory) storing programs for starting the control unit 102. The storage device 502 is a non-volatile, high-capacity storage device that stores programs such as the operating system (OS), applications, and various data.

[0084] The Communication I / F503 includes a variety of communication interfaces for communicating with other devices. For example, the Communication I / F503 includes a NIC (Network Interface Card) for connecting the computer 500 to a communication network N, or a wireless communication interface for wireless WAN (Wide Area Network) communication or wireless LAN communication.

[0085] Output device 504 is, for example, an output device that outputs to the outside, such as a display, speaker, or LED (Light Emitting Diode). Input device 505 is, for example, an input device that accepts input from the outside, such as a touch panel, keyboard, or pointing device. Alternatively, output device 504 and input device 505 may also be display input devices such as touch panel displays.

[0086] The drive device 506 is a device for connecting the storage medium (recording medium) 507 to the computer 500. The storage medium 507 mentioned here includes, for example, media that record information optically, electrically, or magnetically, such as CD-ROMs, floppy disks, and optical discs. Furthermore, the storage medium 507 may also include, for example, semiconductor memories that record information electrically, such as ROMs and flash memory. The bus 508 is connected to all the aforementioned components in a common manner, for example, transmitting address signals, data signals, and various control signals.

[0087] <Processing flow>

[0088] Next, the processing flow of the ventilation control method involved in this embodiment will be described.

[0089] (Adjustment of ventilation volume)

[0090] Figure 6 This is a flowchart illustrating an example of the ventilation volume adjustment process involved in this embodiment. The process illustrates an example of the ventilation volume adjustment process performed by the air conditioning system 1.

[0091] In step S601, the control unit 102 obtains the CO2 concentration (carbon dioxide concentration) of the target area 2. Furthermore, the target area 2 is an example of a space that becomes the object of ventilation by the ventilation device 11.

[0092] Preferably, the control unit 102 acquires CO2 concentration data 111 of the target region 2 measured by the CO2 sensor 12 at a first time interval (e.g., a 1-minute interval), and sets the moving average of the CO2 concentration over a given period (e.g., from the current time up to 10 minutes ago) as the CO2 concentration of the target region 2. This, for example, can reduce the adverse effects of fluctuations in the CO2 concentration data 111 of the target region 2.

[0093] Furthermore, moving average is one example of a process used to smooth the CO2 concentration data 111. The control unit 102 may also use a different method than moving average to smooth the CO2 concentration data 111. In addition, the given time interval (1 minute) and the given period (10 minutes) mentioned above are examples, and other values ​​may also be used.

[0094] Furthermore, the control unit 102 can obtain CO2 concentration data 111 of the target area 2 measured at given time intervals from the storage unit 110, or from the communication device 10. Additionally, the control unit 102 can also obtain the CO2 concentration data 111 of the target area 2 from a cloud service that obtains and manages measurement results from the CO2 sensor 12, or from the CO2 sensor 12 itself. The control unit 102 sets the current value of the CO2 concentration of the target area 2 as the CO2 concentration data 111 of the target area 2 before the processing in step S602, or as the value obtained by smoothing the CO2 concentration data 111 of the target area 2 measured at given time intervals using a method such as moving average.

[0095] In step S602, the control unit 102 determines the ventilation rate of the ventilation device 11 based on the current value of the CO2 concentration in the target area 2 and the time change of the CO2 concentration in the target area 2.

[0096] Preferably, the control unit 102 performs a ventilation volume determination process based on the CO2 concentration of the target region 2 obtained at a first time interval (e.g., a 1-minute interval), and at a second time interval (e.g., a 5-minute interval) that is longer than the first time interval. Several embodiments regarding the ventilation volume determination process will be described later.

[0097] In step S603, the control unit 102 determines whether the newly determined ventilation rate has been changed from the previous ventilation rate during the determination in step S602. If the ventilation rate has been changed, the control unit 102 transfers the processing to step S604. On the other hand, if the ventilation rate has not been changed, the control unit 102 terminates the process. Figure 6 The processing.

[0098] When the process moves to step S604, the control unit 102 instructs the ventilation device 11 to change the ventilation volume. Figure 1 In this example, the control unit 102 sends control data indicating the change in ventilation volume to the communication device 10 for the ventilation device 11 whose ventilation volume is changed. In response, the communication device 10 sends the control data received from the management server 100 to the ventilation device 11, and the ventilation device 11 changes the ventilation volume according to the transmitted control data. In addition, the change in ventilation volume includes starting or stopping the operation of the ventilation device 11.

[0099] (Determination and handling of ventilation volume)

[0100] Next, regarding Figure 6 The process of determining the ventilation volume performed by the control unit 102 in step S602 will be explained.

[0101] [Example 1]

[0102] Figures 7A to 7C This is a diagram used to illustrate the process for determining the ventilation volume involved in Example 1. For example, as... Figure 7A As shown, the control unit 102 can use the corresponding information 710, which is pre-stored with the corresponding information 713 of the ventilation device 11 corresponding to the current value 711 of CO2 concentration and the slope 712 of CO2 concentration, to determine the ventilation volume of the ventilation device 11.

[0103] In the example of corresponding information 710, the ventilation rate 713 of the ventilation device 11 is represented by three levels: "0 (stop)", "L", and "H". Here, "0 (stop)" means that the operation of the ventilation device 11 is stopped. In addition, "L" means that the ventilation device 11 is operated at a low speed, and "H" means that the ventilation device 11 is operated at a high speed. Furthermore, in corresponding information 710, "-Y" is a threshold for a negative slope (e.g., "-2"), and "Z" is a threshold for a positive slope (e.g., "8"). For example, if the current value x of the CO2 concentration in the target area 2 is 850 ppm, and the slope a of the CO2 concentration in the target area 2 is a value between -Y and Z (e.g., "1"), the control unit 102 can determine the ventilation rate of the ventilation device 11 as "L" according to corresponding information 710.

[0104] Here, the slope 'a' is calculated by dividing the current value of CO2 concentration at the current moment by the current value of CO2 concentration one minute ago. For example, the control unit 102 calculates the slope 'a' using the following formula (Equation 1).

[0105] slope a =

[0106] (Current CO2 concentration moving average) - (Current CO2 concentration moving average 1 minute ago) (Equation 1)

[0107] Furthermore, the moving average of the CO2 concentration at the current moment can be calculated by averaging the CO2 concentration over a 10-minute period from the current moment to 10 minutes ago. Similarly, the moving average of the CO2 concentration one minute ago at the current moment can be calculated by averaging the CO2 concentration over a 10-minute period from one minute ago to 11 minutes ago. Additionally, the "current value" can be a moving average as shown in Equation 1, a value obtained by smoothing using other methods, or CO2 concentration data 111 measured by CO2 sensor 12. Furthermore, regarding the calculation of the slope a, "the current value of the CO2 concentration one minute ago" is an example, and the difference between this value and the current value of the CO2 concentration at a given time ago (e.g., 30 seconds, 1 minute, 5 minutes, etc.) can be used.

[0108] As another example, in Figure 7B In the corresponding information 720 shown, the ventilation volume 721 of the ventilation device 11 is represented by five levels: "-2", "-1", "0", "+1", and "+2". Here, "-2" indicates that the ventilation volume level of the ventilation device 11 is reduced by 2 levels, and "-1" indicates that the ventilation volume level of the ventilation device 11 is reduced by 1 level. "0" indicates that the ventilation volume level of the ventilation device 11 remains unchanged. Furthermore, "+1" indicates that the ventilation volume level of the ventilation device 11 is increased by 1 level, and "+2" indicates that the ventilation volume level of the ventilation device 11 is increased by 2 levels. In addition, if the changed ventilation volume level exceeds the maximum value, the control unit 102 sets the ventilation volume level of the ventilation device 11 to the maximum value. Similarly, if the changed ventilation volume level is lower than the minimum value, the control unit 102 sets the ventilation volume level of the ventilation device 11 to the minimum value.

[0109] As yet another example, in Figure 7CIn the corresponding information 730 shown, the ventilation volume 731 of the ventilation device 11 is represented by five levels: "-40%", "-20%", "0", "+20%", and "+40%". Here, "-40%" means reducing the ventilation volume of the ventilation device 11 by 40%, and "-20%" means reducing the ventilation volume of the ventilation device 11 by 20%. "0" means keeping the ventilation volume of the ventilation device 11 unchanged. Furthermore, "+20%" means increasing the ventilation volume of the ventilation device 11 by 20%, and "+40%" means increasing the ventilation volume of the ventilation device 11 by 40%. In addition, if the changed ventilation volume exceeds the maximum value, the control unit 102 sets the ventilation volume of the ventilation device 11 to the maximum value. Similarly, if the changed ventilation volume is lower than the minimum value, the control unit 102 sets the ventilation volume of the ventilation device 11 to the minimum value.

[0110] Such corresponding information 710, 720, and 730 are included, for example, in the setting information 112 pre-stored in the air conditioning system 1. Furthermore, the setting values ​​of the corresponding information 710, 720, and 730 can be changed by an administrator 21 or the like using the administrator terminal 20.

[0111] [Example 2]

[0112] Figure 8A , Figure 8B , Figure 9 This is a diagram used to illustrate the process for determining the ventilation volume involved in Example 2. For example, as... Figure 8A As shown, the control unit 102 can also determine the ventilation rate of the ventilation device 11 based on the arrival time b before the CO2 concentration in the target area 2 reaches the first given value (e.g., 1000 ppm) when the slope a of the CO2 concentration is "a > 0".

[0113] Furthermore, the slope 'a' of the CO2 concentration can be calculated, for example, by subtracting the moving average of the CO2 concentration one minute ago from the moving average of the CO2 concentration at the current moment. Additionally, the arrival time 'b' of the CO2 concentration in target region 2 reaching the first given value can be calculated, for example, using the following (Equation 2) based on the current CO2 concentration 'x' and the slope 'a' of the CO2 concentration.

[0114] Arrival time b = 1 / a × (1000 - x) (Equation 2)

[0115] For example, when the slope a of the CO2 concentration is "a > 0", the control unit 102 controls the ventilation rate of the ventilation device 11 based on the arrival time b as follows.

[0116] If the arrival time b is less than the predetermined first time T1 (e.g., 20 minutes) and more than the predetermined second time T2 (e.g., 10 minutes), the control unit 102 increases the ventilation level of the ventilation device 11 by one level.

[0117] If the arrival time b is less than the second time T2 and is more than or equal to the predetermined third time T3 (e.g., 5 minutes), the control unit 102 increases the ventilation level of the ventilation device 11 by 2 levels.

[0118] If the arrival time is less than the third time T3, the control unit 102 increases the ventilation level of the ventilation device 11 by 3 levels. Furthermore, through the above control, if the ventilation level of the ventilation device 11 exceeds the maximum level, the control unit 102 sets the ventilation level of the ventilation device 11 to the maximum level.

[0119] Here, as an example, the control unit 102 controls the ventilation rate of the ventilation device 11 every 5 minutes, setting the first time T1 to 20 minutes, which is 4 times 5 minutes. Furthermore, the second time T2 is set to 10 minutes, which is 2 times 5 minutes, and the third time T3 is set to 5 minutes. However, the above-mentioned first time T1, second time T2, and third time T3 are just examples; other values ​​are also possible.

[0120] In this way, if the CO2 concentration in the target area 2 reaches the first given value in a shorter time, the control unit 102 preferably sets the ventilation rate of the ventilation device 11 to be larger.

[0121] Preferably, when the CO2 concentration in the target area 2 exceeds a given threshold (e.g., 700 ppm), the control unit 102 performs a process to increase the ventilation rate of the ventilation device 11. Alternatively, when the CO2 concentration in the target area is below the given threshold, the control unit 102 stops the operation of the ventilation device 11.

[0122] In addition, for example, such as Figure 8B As shown, the control unit 102 can also determine the ventilation rate of the ventilation device 11 based on the arrival time b before the CO2 concentration in the target area 2 reaches the second given value (e.g., 800 ppm) when the slope a of the CO2 concentration is "a≤0".

[0123] For example, when the slope a of the CO2 concentration is "a≤0", the control unit 102 controls the ventilation rate of the ventilation device 11 based on the arrival time b as follows.

[0124] If the arrival time b is less than the predetermined fourth time T4 (e.g., 20 minutes) and more than the predetermined fifth time T5 (e.g., 10 minutes), the control unit 102 will reduce the ventilation level of the ventilation device 11 by one level.

[0125] If the arrival time b is less than the 5th time T5 and is more than the predetermined 6th time T6 (e.g., 5 minutes), the control unit 102 reduces the ventilation level of the ventilation device 11 by 2 levels.

[0126] If the arrival time is less than the 6th time T6, the control unit 102 reduces the ventilation volume level of the ventilation device 11 by 3 levels. In addition, through the above control, if the ventilation volume level of the ventilation device 11 is lower than the minimum level, the control unit 102 sets the ventilation volume level of the ventilation device 11 to the minimum level or stops the operation of the ventilation device 11.

[0127] Here, as an example, the fourth time T4 is set to 20 minutes, the fifth time T5 to 10 minutes, and the sixth time to 5 minutes. However, the fourth time T4, the fifth time T5, and the sixth time T6 mentioned above are just one example; other values ​​are also possible.

[0128] In this way, if the CO2 concentration in the target area 2 reaches the second given value in a shorter time, the control unit 102 preferably sets the ventilation rate of the ventilation device 11 to be smaller.

[0129] As another example, for instance, such as Figure 9 As shown, the control unit 102 can also determine the ventilation rate of the ventilation device 11 based on the slope a of the CO2 concentration in the target region 2 when the slope a of the CO2 concentration is "a≤0".

[0130] For example, when the slope a of the CO2 concentration is "a≤0", the control unit 102 controls the ventilation rate of the ventilation device 11 based on the slope a as follows.

[0131] If the slope b is less than the predetermined first slope Y1 (e.g., -2 = -20ppm / 10min) and greater than the predetermined second slope Y2 (e.g., -5 = -50ppm / 10min), the control unit 102 reduces the ventilation rate of the ventilation device 11 by one level.

[0132] If the slope b is less than the second slope Y2, or if the CO2 concentration in the target area 2 is lower than a given threshold (e.g., 700 ppm), the control unit 102 will reduce the ventilation rate of the ventilation device 11 by 2 levels.

[0133] In addition, through the above control, when the ventilation volume level of the ventilation device 11 is lower than the minimum level, the control unit 102 sets the ventilation volume level of the ventilation device 11 to the minimum level or stops the operation of the ventilation device 11.

[0134] Preferably, when the CO2 concentration in the target area 2 is below a first given value (e.g., 1000 ppm), the control unit 102 performs a process to reduce the ventilation volume of the ventilation device 11.

[0135] [Example 3]

[0136] Figure 10 Figure (1) illustrates the process for determining the ventilation volume involved in Example 3. The control unit 102 may, for example, use the difference c between the current value of CO2 concentration in the target area 2 and the given value of CO2 concentration (e.g., 1000 ppm), and the slope (time change) a of CO2 concentration, to adjust the ventilation volume of the ventilation device 11.

[0137] Figures 11A to 11C Figures (2) to (4) illustrate the process for determining the ventilation volume involved in Example 3. The control unit 102, for example, is... Figure 11A As shown, the ventilation rate of the ventilation device 11 can also be determined by using the pre-stored information 1110 corresponding to the ventilation rate 1113 of the ventilation device 11 corresponding to the difference 1111 between the given value of CO2 concentration and the current value of CO2 concentration, and the slope 1112 of CO2 concentration.

[0138] In the example of corresponding information 1110, the ventilation rate 1113 of the ventilation device 11 is represented by three levels: "0 (stop)", "L", and "H". Here, "0 (stop)" means that the operation of the ventilation device 11 is stopped. In addition, "L" means that the ventilation device 11 is operated weakly, and "H" means that the ventilation device 11 is operated strongly. Furthermore, in corresponding information 1110, "-Y" is a threshold for a negative slope (e.g., "-2"), and "Z" is a threshold for a positive slope (e.g., "8"). For example, if the difference c between the given value of CO2 concentration and the current value of CO2 concentration is 100, and the slope a of CO2 concentration is a value between Y and Z (e.g., "5"), the control unit 102 can determine the ventilation rate of the ventilation device 11 as "L" according to corresponding information 1110.

[0139] As another example, in Figure 11BIn the corresponding information 1120 shown, the ventilation volume 1121 of the ventilation device 11 is represented by five levels: "-2", "-1", "0", "+1", and "+2". Here, "-2" indicates that the ventilation volume level of the ventilation device 11 is reduced by 2 levels, and "-1" indicates that the ventilation volume level of the ventilation device 11 is reduced by 1 level. "0" indicates that the ventilation volume level of the ventilation device 11 remains unchanged. Furthermore, "+1" indicates that the ventilation volume level of the ventilation device 11 is increased by 1 level, and "+2" indicates that the ventilation volume level of the ventilation device 11 is increased by 2 levels. In addition, if the changed ventilation volume level exceeds the maximum value, the control unit 102 sets the ventilation volume level of the ventilation device 11 to the maximum value. Similarly, if the changed ventilation volume level is lower than the minimum value, the control unit 102 sets the ventilation volume level of the ventilation device 11 to the minimum value or stops the operation of the ventilation device 11.

[0140] As another example, in Figure 11C In the corresponding information 1130 shown, the ventilation volume 1131 of the ventilation device 11 is represented by five levels: "-40%", "-20%", "0", "+20%", and "+40%". Here, "-40%" means reducing the ventilation volume of the ventilation device 11 by 40%, and "-20%" means reducing the ventilation volume of the ventilation device 11 by 20%. "0" means keeping the ventilation volume of the ventilation device 11 unchanged. Furthermore, "+20%" means increasing the ventilation volume of the ventilation device 11 by 20%, and "+40%" means increasing the ventilation volume of the ventilation device 11 by 40%. In addition, if the changed ventilation volume exceeds the maximum value, the control unit 102 sets the ventilation volume of the ventilation device 11 to the maximum value. Similarly, if the changed ventilation volume is lower than the minimum value, the control unit 102 sets the ventilation volume of the ventilation device 11 to the minimum value or stops the operation of the ventilation device 11.

[0141] Such corresponding information 1110, 1120, and 1130 is included, for example, in the setting information 112 pre-stored in the air conditioning system 1. Furthermore, the setting values ​​of corresponding information 1110, 1120, and 1130 can be changed by an administrator 21 or the like using an administrator terminal 20.

[0142] In addition, the control unit 102 can also determine the ventilation volume of the ventilation device 11 without relying on the corresponding information 1110, 1120, 1130.

[0143] For example, when the slope a of the CO2 concentration is "a > 0", the control unit 102 can control the ventilation volume of the ventilation device 11 based on the difference c between the given value of the CO2 concentration and the current value of the CO2 concentration.

[0144] When the difference c between a given value of CO2 concentration and the current value of CO2 concentration satisfies c < T7 × a, the control unit 102 increases the ventilation level of the ventilation device 11 by one level. Here, T7 is a preset 7th time T7 (e.g., 20 minutes), and a is the slope a of the CO2 concentration.

[0145] When the difference *c* between a given CO2 concentration and the current CO2 concentration satisfies *c* < *T8* × *a*, the control unit 102 increases the ventilation rate level of the ventilation device 11 by two levels. Here, *T8* is a preset 8th time interval (e.g., 10 minutes). Furthermore, through the above control, if the ventilation rate level of the ventilation device 11 exceeds the maximum level, the control unit 102 sets the ventilation rate level of the ventilation device 11 to the maximum level.

[0146] In addition, when the slope a of the CO2 concentration is "a≤0", the control unit 102 can control the ventilation volume of the ventilation device 11 based on the slope a of the CO2 concentration as follows.

[0147] When the slope 'a' of the CO2 concentration satisfies a < A1, the control unit 102 reduces the ventilation rate of the ventilation device 11 by one level. Here, A1 is a predetermined first slope (e.g., -5).

[0148] When the slope 'a' of the CO2 concentration satisfies a < A2, the control unit 102 reduces the ventilation rate of the ventilation device 11 by two levels. Here, A2 is a predetermined second slope (e.g., -10). Furthermore, through the above control, if the ventilation rate of the ventilation device 11 is below the minimum level, the control unit 102 sets the ventilation rate of the ventilation device 11 to the minimum level or stops the operation of the ventilation device 11.

[0149] The control unit 102, for example through the above embodiments 1 to 3, can determine the ventilation rate of the ventilation device 11 based on the current value of the CO2 concentration in the target area 2 and the time change of the CO2 concentration.

[0150] [Example 4]

[0151] In Example 4, an example of processing is described in which the air conditioning system 1 includes multiple ventilation devices 11, and the control unit 102 adjusts the ventilation volume of the multiple ventilation devices 11 based on the current value of the CO2 concentration in the target area 2 and the time change of the CO2 concentration in the target area 2.

[0152] (Adjustment of ventilation volume 1)

[0153] Figure 12 This is a flowchart (1) illustrating an example of the ventilation volume adjustment process involved in Example 4. Furthermore, details regarding the use of… are omitted here. Figure 6The instructions for adjusting the ventilation volume are the same as those for detailed treatment.

[0154] In step S1201, the control unit 102 obtains the CO2 concentration (carbon dioxide concentration) of the target region 2. Here, for example, as... Figure 13 As shown, a CO2 sensor 12 is provided in the target area 2. Furthermore, the CO2 sensor 12 is provided, for example, in a crowded area of ​​the target area 2, and the control unit 102 adjusts the ventilation rate of the ventilation device 11b located near the CO2 sensor.

[0155] Preferably, the control unit 102 acquires CO2 concentration data 111 of the target region 2 measured by the CO2 sensor 12 at a first time interval (e.g., a 1-minute interval), and sets the moving average of the CO2 concentration over a given period (e.g., from the current time up to 10 minutes ago) as the CO2 concentration of the target region 2. Furthermore, the moving average is an example of smoothing the CO2 concentration data 111. The control unit 102 may also use methods other than the moving average to smooth the concentration data 111.

[0156] In step S1202, the control unit 102 determines the ventilation rate of the ventilation device 11b based on the current value of the CO2 concentration in the target area 2 and the time change of the CO2 concentration in the target area 2.

[0157] Preferably, the control unit 102 performs a ventilation volume determination process based on the CO2 concentration of the target region 2 obtained at a first time interval (e.g., a 1-minute interval), at a second time interval (e.g., a 5-minute interval) that is longer than the first time interval. Furthermore, the ventilation volume determination process can, for example, be applied to the processes described in Examples 1-3.

[0158] In step S1203, the control unit 102 determines whether the ventilation rate of the ventilation device 11b has changed. If the ventilation rate has changed, the control unit 102 transfers the processing to step S1204. On the other hand, if the ventilation rate has not changed, the control unit 102 terminates the process. Figure 12 The processing.

[0159] When the process moves to step S1204, the control unit 102 instructs the ventilation device 11b to change the ventilation volume. Figure 1 In this example, the control unit 102 sends control data indicating the change in ventilation volume to the communication device 10 for the ventilation device 11b where the ventilation volume has been changed. In response, the communication device 10 forwards the control data received from the management server 100 to the ventilation device 11b, and the ventilation device 11b adjusts the ventilation volume according to the forwarded control data.

[0160] In addition, if there are two or more CO2 sensors 12 in the target area 2, the control unit 102 only needs to perform the same processing for each of the ventilation devices 11 that are close to each CO2 sensor 12.

[0161] Figure 12 The process shown is one example. Control unit 102 can also be replaced... Figure 12 The process shown, for example, is to perform Figure 14 The ventilation volume is adjusted as shown.

[0162] (Adjustment of ventilation volume 2)

[0163] Figure 14 This is a flowchart (2) illustrating an example of the ventilation volume adjustment process involved in Example 4. Additionally, details regarding the adjustment process in... Figure 6 , 12 The same detailed explanation of the adjustment process for ventilation volume is provided in the text.

[0164] In step S1401, the control unit 102 obtains the CO2 concentration (carbon dioxide concentration) of the target region 2. Here, for example, as... Figure 13 As shown, a CO2 sensor 12 is installed in the target area 2, and the control unit 102 adjusts the ventilation volume of the ventilation devices 11a, 11b, and 11c installed in the target area 2.

[0165] Preferably, the control unit 102 acquires CO2 concentration data 111 of the target area 2 measured by the CO2 sensor 12 at a first time interval (e.g., a 1-minute interval), and sets the moving average of the CO2 concentration over a given period (e.g., from the current time up to 10 minutes ago) as the CO2 concentration of the target area 2.

[0166] In step S1402, the control unit 102 determines the ventilation rate of the ventilation devices 11a, 11b, and 11c based on the current value of the CO2 concentration in the target area 2 and the time change of the CO2 concentration in the target area 2.

[0167] Preferably, the control unit 102 performs a ventilation volume determination process based on the CO2 concentration of the target region 2 obtained at a first time interval (e.g., a 1-minute interval), at a second time interval (e.g., a 5-minute interval) that is longer than the first time interval. As an example, the control unit 102 may also control the ventilation devices 11a, 11b, and 11c to achieve the same ventilation volume.

[0168] As another example, the ventilation devices 11a, 11b, and 11c can be pre-weighted based on factors such as where people tend to gather or where carbon dioxide tends to accumulate, and the ventilation rates of the ventilation devices 11a, 11b, and 11c can be controlled to achieve different ventilation rates. In this case, the control unit 102 can also apply the processing described in Examples 1 to 3 to determine the ventilation rate of the ventilation device 11b near the CO2 sensor 12, and determine the ventilation rates of the ventilation devices 11a and 11c based on the determined ventilation rate of the ventilation device 11b and the weights of the ventilation devices 11a, 11b, and 11c.

[0169] In step S1403, the control unit 102 determines whether the ventilation rate of the ventilation devices 11a, 11b, and 11c has changed. If the ventilation rate has changed, the control unit 102 transfers the processing to step S1404. On the other hand, if the ventilation rate has not changed, the control unit 102 terminates the process. Figure 12 The processing.

[0170] When the process moves to step S1404, the control unit 102 instructs the ventilation device 11 in which the ventilation volume has been changed to change the ventilation volume of the ventilation devices 11a, 11b, and 11c.

[0171] Furthermore, if two or more CO2 sensors 12 are installed in the target area 2, the ventilation devices 11 corresponding to the CO2 sensors 12 can be pre-grouped, and the control unit 102 can execute for each group. Figure 14 The processing.

[0172] <Regarding the effect>

[0173] Figure 15 This diagram illustrates the effects of the air conditioning system 1 according to this embodiment. Figure 15 In Chart 1500, the horizontal axis represents the number of people located in object area 2, and the vertical axis represents the ventilation volume. The ventilation volume is the sum of the ventilation volumes of multiple ventilation devices 11. Level 4 corresponds to the sum of the ventilation volumes when all ventilation devices 11 are at "strong" ventilation volume, and Level 3 corresponds to the sum of the ventilation volumes when all ventilation devices 11 are at "weak" ventilation volume. In addition, Level 2 corresponds to the sum of the ventilation volumes when ventilation devices 11 with "weak" ventilation volume and ventilation devices 11 with "stopped" ventilation volume are mixed together, and Level 1 corresponds to the sum of the ventilation volumes when all ventilation devices 11 are "stopped".

[0174] In Figure 1500, state (1) refers to a situation where there are nearly enough people in object area 2, the CO2 concentration in object area 2 is around 1000 ppm when the ventilation rate is level 4, and the CO2 concentration in object area 2 exceeds 1000 ppm when the ventilation rate is level 3. State (2) refers to a situation where there are fewer people in object area 2 than the required number, the CO2 concentration in object area 2 is approximately 800 ppm to 1000 ppm when the ventilation rate is level 4, and the CO2 concentration in object area 2 exceeds 850 ppm but is below 1000 ppm when the ventilation rate is level 3. State (3) refers to a situation where there are few people in object area 2, the CO2 concentration in object area 2 is below 850 ppm when the ventilation rate is level 3, and the CO2 concentration in object area 2 exceeds 1000 ppm when the ventilation rate is level 1. State (4) refers to a situation where there are even fewer people in object area 2, and the CO2 concentration in object area 2 exceeds 700 ppm but is below 1000 ppm when the ventilation rate is level 1.

[0175] Furthermore, line 1 (1501) shows the relationship between the number of people with a CO2 concentration of 1000 ppm and the ventilation rate. Line 2 (1502) shows the relationship between the number of people with a CO2 concentration of 850 ppm and the ventilation rate. Line 3 (1503) shows the relationship between the number of people with a CO2 concentration of 700 ppm and the ventilation rate.

[0176] Furthermore, the threshold control 1511 indicates that when the CO2 concentration in the target area 2 is between 700 ppm and 850 ppm, the ventilation rate is set to level 3; when it exceeds 850 ppm, the ventilation rate is set to level 4; and when it is below 700 ppm, the ventilation rate is set to level 1. In this embodiment, the line 1511 indicates the control of the ventilation rate for all ventilation devices 11 according to this embodiment.

[0177] In state (1), both threshold control 1511 and 1512 of this embodiment have an air exchange rate of level 4 (the air exchange rate of all ventilation devices 11 is "strong").

[0178] When the number of people in the target area 2 decreases and the state changes from (1) to (2), in this embodiment 1512, based on the current value of CO2 concentration and the change over time, the ventilation rate is switched from level 4 to level 3 (the ventilation rate of all ventilation devices 11 is "weak"). On the other hand, in threshold control 1511, ventilation is continued at level 4 until the CO2 concentration in the target area 2 becomes below 850 ppm.

[0179] When the number of people in target area 2 decreases further, in this embodiment 1512, the ventilation rate can be further reduced by one level based on the current value of CO2 concentration and changes over time. For example, in Figure 15 In the example, the air conditioning system 1 changes the ventilation volume from level 3 to level 2 (the ventilation device 11 with a "weak" ventilation volume and the ventilation device 11 with a "stop" ventilation volume are mixed together).

[0180] When the number of people in object area 2 is further reduced and the state changes from (2) to (3), the ventilation volume of all ventilation devices 11 in threshold control 1511 is switched from level 4 to level 3.

[0181] When the number of people in the target area 2 further decreases, and the state changes from (3) to (4), in this embodiment 1512, the ventilation rate of all ventilation devices 11 can be changed to level 1 (stop the operation of all ventilation devices 11) based on the current value of CO2 concentration and the change over time. On the other hand, in threshold control 1511, the ventilation rate is continuously ventilated at level 3 until the CO2 concentration in the target area 2 becomes below 700 ppm.

[0182] Thus, according to this embodiment, ventilation can be performed for the minimum required time and amount while ensuring that the carbon dioxide concentration in the space to be ventilated does not exceed a given value. Therefore, according to this embodiment, the ventilation volume of the air conditioning system 1 can be reduced. Furthermore, by reducing the ventilation volume, the load on the air conditioning unit 13 of the air conditioning system 1 can also be reduced.

[0183] <Summary>

[0184] The air conditioning system 1 of the present invention includes a ventilation device 11 and a control unit 102 for controlling the ventilation device 11. The control unit 102 obtains the CO2 concentration (carbon dioxide concentration) of the target area 2 that is the ventilation target of the ventilation device 11, and adjusts the ventilation volume of the ventilation device 11 based on the current value of the CO2 concentration and the time change of the CO2 concentration.

[0185] According to the air conditioning system 1, in the air conditioning system 1 including the ventilation device 11, the CO2 concentration in the target area 2 that is the object of ventilation does not exceed a given value, and the required minimum time and amount of ventilation can be performed.

[0186] Preferably, the control unit 102 uses the current value of the CO2 concentration in the target area 2, a given value for the CO2 concentration, and the time variation of the CO2 concentration in the target area 2 to adjust the ventilation rate of the ventilation device 11. Therefore, the control unit 102 can utilize the information on the time variation of the CO2 concentration in the target area 2 to suppress the situation where the CO2 concentration in the target area 2 reaches the given concentration, and to suppress the ventilation rate.

[0187] Preferably, the control unit 102 uses the difference between the current value of the CO2 concentration in the target region 2 and the given value of the CO2 concentration, as well as the time change of the CO2 concentration in the target region 2, to adjust the ventilation rate of the ventilation device 11. Therefore, the control unit 102 can use the information of the difference between the current value of the CO2 concentration in the target region 2 and the given value of the CO2 concentration to suppress the situation where the CO2 concentration in the target region 2 reaches the given concentration, and suppress the ventilation rate.

[0188] Preferably, the control unit 102 calculates the arrival time when the CO2 concentration in the target area 2 reaches a given value (as a given CO2 concentration) based on the current value of the CO2 concentration in the target area 2 and the time change of the CO2 concentration in the target area 2, and adjusts the ventilation rate of the ventilation device 11 based on the calculated arrival time. Therefore, the control unit 102 can use the information of the arrival time before the CO2 concentration in the target area 2 reaches the given value (as a given CO2 concentration) to suppress the situation where the CO2 concentration in the target area 2 reaches the given concentration, and suppress the ventilation rate.

[0189] Preferably, when the current value of the CO2 concentration in the target area 2 is less than a predetermined first given value of the CO2 concentration, and the time until the CO2 concentration in the target area 2 reaches the first given value is within a first time, the control unit 102 increases the ventilation rate of the ventilation device 11 by a first increase.

[0190] Preferably, when the arrival time is within a second time shorter than the first time, the control unit 102 increases the ventilation rate of the ventilation device 11 by a second increase that is larger than the first increase. As a result, even when the CO2 concentration in the target area 2 rises rapidly, the air conditioning system 1 can ensure that the CO2 concentration in the target area 2 does not exceed the first given value and can suppress the ventilation rate.

[0191] Preferably, when the current value of the CO2 concentration in the target area 2 is greater than a predetermined second given value of the CO2 concentration, and the time until the CO2 concentration in the target area 2 reaches the second given value is within a third time, the control unit 102 reduces the ventilation rate of the ventilation device 11 by a first reduction.

[0192] Preferably, if the control unit 102 reduces the ventilation rate of the ventilation device 11 by a second reduction greater than the first reduction rate, or stops the operation of the ventilation device 11, when the time for the CO2 concentration in the target area 2 to reach the second given value is within a fourth time shorter than the third time, the control unit 102 reduces the ventilation rate of the ventilation device 11 by a second reduction rate greater than the first reduction rate. Therefore, the air conditioning system 1 can suppress the ventilation rate when the CO2 concentration in the target area 2 decreases rapidly.

[0193] Preferably, the control unit 102 stops the operation of the ventilation device 11 when the current value of the CO2 concentration in the target area 2 is below a predetermined threshold value of the CO2 concentration.

[0194] Preferably, the air conditioning system 1 includes a plurality of ventilation devices 11, and the control unit 102 adjusts the ventilation volume of the plurality of ventilation devices based on the current value of the carbon dioxide concentration and the time change of the carbon dioxide concentration.

[0195] Preferably, the time interval for the control unit 102 to determine the air exchange rate of the ventilation device 11 is longer than the time interval for measuring the CO2 concentration in the target area 2.

[0196] Preferably, the control unit 102 smooths the obtained CO2 concentration of the target area 2 to calculate the time variation of the CO2 concentration of the target area 2. As a result, the air conditioning system 1 can reduce the adverse effects caused by fluctuations in the CO2 concentration data of the target area 2.

[0197] Preferably, the air conditioning system 1 includes an air exchange device 11 and a communication device 10 capable of communicating with the air exchange device 11, the communication device 10 having a control unit 102.

[0198] In an air conditioning system 1 including a ventilation device 11 and a control unit 102 for controlling the ventilation device 11, the ventilation control method of the present invention obtains the CO2 concentration of the target area 2 that is the ventilation target of the ventilation device 11, and adjusts the ventilation volume of the ventilation device 11 based on the current value of the CO2 concentration of the target area 2 and the time change of the CO2 concentration of the target area 2.

[0199] The embodiments have been described above, but it is understood that various changes in manner or details can be made without departing from the spirit and scope of the claims.

[0200] This application claims priority based on Japanese Patent Application No. 2023-115680, filed with the Japan Patent Office on July 14, 2023, the entire contents of which are incorporated herein by reference.

[0201] Label Explanation

[0202] 1: Air conditioning system

[0203] 2: Target area (the space that becomes the target of ventilation)

[0204] 10: Communication device

[0205] 11, 11a, 11b, 11c: Ventilation devices

[0206] 12: CO2 sensor

[0207] 100: Management Server

[0208] 102: Control Department

[0209] 500: Computer

[0210] N: Communication network.

Claims

1. An air conditioning system, comprising a ventilation device and a control unit for controlling the ventilation device, The control unit, Obtain the carbon dioxide concentration of the space to be ventilated by the ventilation device. Using the current value of the carbon dioxide concentration and the time change of the carbon dioxide concentrations preceding the current value relative to the current value, the arrival time before the carbon dioxide concentration reaches the upper or lower limit of the adjustment range of the carbon dioxide concentration is calculated. The ventilation rate of the ventilation device is adjusted based on the arrival time.

2. The air conditioning system according to claim 1, wherein, When the current value of the carbon dioxide concentration is less than the upper limit value and the time before the carbon dioxide concentration reaches the upper limit value is within the first time, the control unit increases the ventilation rate of the ventilation device by a first increment.

3. The air conditioning system according to claim 2, wherein, When the arrival time is within a second time shorter than the first time, the control unit increases the ventilation volume of the ventilation device by a second increase that is greater than the first increase.

4. The air conditioning system according to claim 1, wherein, If the current value of the carbon dioxide concentration is greater than the lower limit value, and the time before the carbon dioxide concentration reaches the lower limit value is within the third time, the control unit reduces the ventilation rate of the ventilation device by a first reduction.

5. The air conditioning system according to claim 4, wherein, If the arrival time is within a fourth time that is shorter than the third time, the control unit reduces the ventilation volume of the ventilation device by a second decrease that is larger than the first decrease, or stops the operation of the ventilation device.

6. The air conditioning system according to any one of claims 1 to 5, wherein, When the current carbon dioxide concentration is below a given threshold value that is smaller than the lower limit value, the control unit stops the operation of the ventilation device.

7. The air conditioning system according to any one of claims 1 to 5, wherein, The air conditioning system includes multiple air exchange devices. The control unit adjusts the ventilation volume of the plurality of ventilation devices based on the arrival time.

8. The air conditioning system according to any one of claims 1 to 5, wherein, The control unit determines that the time interval for measuring the ventilation rate is longer than the time interval for measuring the carbon dioxide concentration.

9. The air conditioning system according to any one of claims 1 to 5, wherein, The control unit smooths the obtained carbon dioxide concentration to calculate the time change of the carbon dioxide concentration.

10. The air conditioning system according to any one of claims 1 to 5, wherein, The air conditioning system includes the ventilation device and a communication device capable of communicating with the ventilation device. The communication device has the control unit.

11. A ventilation control method in an air conditioning system including a ventilation device and a control unit for controlling the ventilation device, The control unit, Obtain the carbon dioxide concentration of the space to be ventilated by the ventilation device. Using the current value of the carbon dioxide concentration and the time change of the carbon dioxide concentrations preceding the current value relative to the current value, the arrival time before the carbon dioxide concentration reaches the upper or lower limit of the adjustment range of the carbon dioxide concentration is calculated. The ventilation rate of the ventilation device is adjusted based on the arrival time.

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