JP2019184082A - Method and device for controlling concentration of carbon dioxide - Google Patents

Abstract

To realize a method for controlling carbon dioxide, capable of reducing influence that the concentration of carbon dioxide affects human beings.SOLUTION: A method for controlling the concentration of carbon dioxide comprises: a detection step of detecting people existing in a space where a person to be controlled exists; and a carbon dioxide concentration adjusting step in which (i) the person is detected in the space, and (ii) the concentration of carbon dioxide in the space is reduced so as to be equal to or lower than a predetermined reference concentration when the concentration of carbon dioxide in the space is higher than the predetermined reference concentration.SELECTED DRAWING: Figure 3

Description

  The present disclosure relates to a carbon dioxide concentration control method and a carbon dioxide concentration control device in a predetermined space.

  Patent Document 1 discloses a ventilation system that can control a ventilation path for ventilation according to an indoor environment. The ventilation system is provided in a plurality of rooms and includes a plurality of sensors that detect the concentration of contaminants contained in room air, and each room is defined as an exhaust room and an air supply room based on the contaminant concentration values. Classify. Further, the ventilation system sets the ventilation device of each room to the exhaust operation and the air supply operation according to the classification, and controls the ventilation path based on the setting.

JP 2005-201592 A (published July 28, 2005)

  However, the ventilation system disclosed in Patent Document 1 only performs ventilation by classifying the exhaust room and the supply room based on the magnitude relationship of the contaminant concentration for each room. For this reason, no consideration is given to the influence of the contaminant concentration on human work efficiency.

  An object of one embodiment of the present disclosure is to realize a carbon dioxide concentration control method and the like that can reduce the influence of the carbon dioxide concentration on human work efficiency.

  In order to solve the above problem, a carbon dioxide concentration control method according to an aspect of the present disclosure is a carbon dioxide concentration control method for controlling the concentration of carbon dioxide in a space where a person exists, which is a control target, A detection step of detecting a person existing in the space; (i) the detection of the person in the space in the detection step; and (ii) a concentration of carbon dioxide in the space in consideration of the work efficiency of the person And a carbon dioxide concentration adjusting step for reducing the concentration of carbon dioxide in the space so that the concentration is equal to or lower than the predetermined reference concentration.

  A carbon dioxide concentration control device according to an aspect of the present disclosure is a carbon dioxide concentration control device that controls the concentration of carbon dioxide in a space where a person exists, which is a control target. A detection unit to detect, and (i) the detection unit detects the person in the space, and (ii) a concentration of carbon dioxide in the space is higher than a predetermined reference concentration considering the work efficiency of the person And a carbon dioxide concentration adjusting unit that reduces the concentration of carbon dioxide in the space so that the concentration is equal to or lower than the predetermined reference concentration.

  According to the carbon dioxide concentration control method and the carbon dioxide concentration control apparatus according to one aspect of the present disclosure, it is possible to reduce the influence of the carbon dioxide concentration on human work efficiency.

1 is a block diagram illustrating a configuration of a carbon dioxide control system according to Embodiment 1. FIG. It is a figure which shows the structure of the carbon dioxide concentration adjustment part with which the carbon dioxide control apparatus which concerns on Embodiment 1 is provided. 3 is a flowchart illustrating a carbon dioxide control method executed by the carbon dioxide control device according to the first embodiment. It is a graph which shows the relationship between the carbon dioxide concentration in a laboratory, and the average value of the ratio of the number of correct input characters. It is a block diagram which shows the structure of the carbon dioxide control system which concerns on Embodiment 2. FIG. It is a flowchart which shows the carbon dioxide control method which the carbon dioxide control apparatus which concerns on Embodiment 2 performs. It is a block diagram which shows the structure of the carbon dioxide control system which concerns on Embodiment 3. It is a figure which shows the structure of the carbon dioxide adjusting device with which the carbon dioxide control system which concerns on Embodiment 3 is provided. It is a block diagram which shows the structure of the carbon dioxide control system which concerns on Embodiment 4. It is a figure which shows the structure of the carbon dioxide adjusting device with which the carbon dioxide control apparatus which concerns on Embodiment 4 is provided. 6 is a flowchart illustrating a carbon dioxide control method executed by a carbon dioxide control device according to a fourth embodiment.

Embodiment 1
Hereinafter, an embodiment of the present disclosure will be described in detail.

(Configuration of carbon dioxide control system 1)
FIG. 1 is a block diagram illustrating a configuration of a carbon dioxide control system 1 according to the present embodiment. As shown in FIG. 1, the carbon dioxide control system 1 includes a carbon dioxide control device 10 (carbon dioxide concentration control device), a human detection sensor 20, a carbon dioxide concentration sensor 30, and a carbon dioxide concentration reduction device 40. . The carbon dioxide control system 1 is provided in a closed space such as an office, for example, and controls the concentration of carbon dioxide in a space 100 (a space in which a person exists as a control target) included in the closed space.

  The closed space is a space in which a predetermined sealing is possible and the person 200 works inside. The closed space may be a living space such as a house, or a space in a transportation facility such as a car or a railroad, in addition to a workplace space such as the office described above. Further, “predetermined sealing is possible” means that a person can voluntarily enhance the sealing performance of the space by closing a window, for example. In addition, it is not a person, for example, air conditioning equipment etc. judge the necessity of enhancing the sealing performance of the space based on the temperature or humidity of the space, etc., and the automatic opening and closing device of the window closes the window based on the judgment result, etc. An operation for increasing the sealing performance of the space may be performed.

  The space 100 is a region near the person 200 in the closed space. For example, the space 100 may be a region having a radius of 1 m centered on the person 200. This area is almost equal to the area of a desk installed in a general office.

  The human detection sensor 20, the carbon dioxide concentration sensor 30, and the carbon dioxide concentration reducing device 40 are provided in a closed space including the space 100. Thereby, the person detection sensor 20 and the carbon dioxide concentration sensor 30 can detect the person 200 or the carbon dioxide concentration in the space 100, respectively. Further, the carbon dioxide concentration reducing device 40 reduces the carbon dioxide concentration in the space 100 by reducing the carbon dioxide concentration in the closed space.

  The human detection sensor 20, the carbon dioxide concentration sensor 30, and the carbon dioxide concentration reducing device 40 are preferably installed in a region within a radius of 1 m from the person 200. In other words, the human detection sensor 20, the carbon dioxide concentration sensor 30, and the carbon dioxide concentration reducing device 40 are preferably provided in the space 100. Specifically, the human detection sensor 20, the carbon dioxide concentration sensor 30, and the carbon dioxide concentration reduction device 40 may be disposed on a desk on which the person 200 is working, for example. In this case, the human detection sensor 20 and the carbon dioxide concentration sensor 30 can detect the person 200 or the carbon dioxide concentration in the space 100 more accurately. Further, the carbon dioxide concentration reducing device 40 can effectively reduce the carbon dioxide concentration in the space 100.

  The carbon dioxide control device 10 controls the operation of the carbon dioxide control system 1. A specific configuration of the carbon dioxide control device 10 will be described later.

  The human detection sensor 20 is a sensor that detects whether or not a person 200 exists in the space 100 and transmits a detection result to the detection unit 11 (described later). The human detection sensor 20 may be a human sensor using, for example, infrared rays, ultrasonic waves, or visible light.

  The carbon dioxide concentration sensor 30 is a sensor that detects the concentration of carbon dioxide in the space 100 at a predetermined time interval and transmits it to the carbon dioxide concentration acquisition unit 12 (described later). Although the detection method of the carbon dioxide by the carbon dioxide concentration sensor 30 is not specifically limited, For example, a semiconductor system, an electrochemical system, or an infrared absorption system may be used.

When the carbon dioxide concentration sensor 30 detects carbon dioxide by a semiconductor method, examples of the semiconductor include SnO ₂ or ZnO. In particular, it is preferable to use a semiconductor in which La is added to SnO ₂ . An apparatus for detecting carbon dioxide by a semiconductor method is small and low-cost. For this reason, when the carbon dioxide concentration sensor 30 detects carbon dioxide by a semiconductor method, the entire carbon dioxide control system 1 can be configured in a small size and at low cost.

  On the other hand, when the carbon dioxide concentration sensor 30 detects the concentration of carbon dioxide by an electrochemical method or an infrared absorption method, the carbon dioxide concentration can be detected with high accuracy. For this reason, the carbon dioxide control apparatus 10 can control the carbon dioxide concentration in the space 100 more precisely.

  The carbon dioxide concentration reducing device 40 reduces the concentration of carbon dioxide in the space 100. A specific configuration of the carbon dioxide concentration reducing device 40 will be described later.

  The carbon dioxide control system 1 further includes a storage unit 90. The storage unit 90 stores information necessary for control by the carbon dioxide control device 10. Specifically, the storage unit 90 stores data indicating detection results obtained by the human detection sensor 20 and the carbon dioxide concentration sensor 30, for example. The storage unit 90 may be a semiconductor memory, for example.

(Configuration of carbon dioxide control device 10)
The carbon dioxide control device 10 includes a detection unit 11, a carbon dioxide concentration acquisition unit 12, and a control unit 13 (carbon dioxide concentration adjustment unit).

  The detection unit 11 acquires information indicating whether or not the person 200 exists in the space 100 from the human detection sensor 20 and transmits the information to the control unit 13. The carbon dioxide concentration acquisition unit 12 acquires information indicating the carbon dioxide concentration in the space 100 from the carbon dioxide concentration sensor 30 and transmits the information to the control unit 13.

  Based on the information received from the detection unit 11, the control unit 13 determines whether the human detection sensor 20 detects the person 200 in the space 100. Further, the control unit 13 determines whether or not the concentration of carbon dioxide in the space 100 is higher than a predetermined reference concentration.

  The control unit 13 (i) detects the person 200 in the space 100 and (ii) the carbon dioxide concentration in the space 100 when the concentration of the carbon dioxide in the space 100 is higher than a predetermined reference concentration. The concentration of carbon dioxide in the space 100 is reduced so that the concentration is equal to or lower than a predetermined reference concentration considering the work efficiency of the person 200. Specifically, the control unit 13 transmits a control signal for operating a blower mechanism 44 (described later) to a blower control unit 46 (described later) included in the carbon dioxide concentration reducing device 40.

  As a result of earnest research, the inventor of the present application has found that carbon dioxide concentration in a space near a person affects the work amount (work efficiency) per unit time of the person. The work efficiency here is evaluated using the work amount per unit time as an index. The amount of work is measured by a pseudo task such as a first addition work or text typing. If the work efficiency is improved, the value of the business activities and the economic value of the company performing the work are improved. Therefore, improving work efficiency is important for companies.

  Specifically, the inventor of the present application has found that when the carbon dioxide concentration in the space near the person exceeds 3500 ppm, the work efficiency of the person is significantly reduced. Based on this knowledge, the reference concentration is preferably set to 3500 ppm or less. Further, the inventor of the present application has found that when the carbon dioxide concentration in the space near the person is less than 1500 ppm, the work amount of the person hardly changes compared to the case where the carbon dioxide concentration in the space is 600 ppm. I found. Therefore, the reference concentration is preferably set to 600 ppm or more. That is, the reference concentration is preferably set to 600 ppm or more and 3500 ppm or less.

  In the present embodiment, the predetermined reference concentration is 3500 ppm. Examples of experiments conducted to obtain the above findings will be described later.

(Configuration of carbon dioxide concentration reducing device 40)
FIG. 2 is a diagram illustrating a configuration of the carbon dioxide concentration reducing device 40 included in the carbon dioxide control system 1. As shown in FIG. 2, the carbon dioxide concentration reducing device 40 includes an inlet 41, an outlet 42, a flow path 43, a blower mechanism 44, a carbon dioxide absorber 45, and a blower controller 46. .

  The inlet 41 is an inlet through which air flows into the carbon dioxide concentration reducing device 40. The outlet 42 is an outlet from which air flows out from the carbon dioxide concentration reducing device 40. The channel 43 is a channel through which air flows from the inlet 41 to the outlet 42 in the carbon dioxide concentration reducing device 40. The length and cross-sectional shape of the flow path 43 are not particularly limited, and may be arbitrarily set depending on the size and application of the carbon dioxide concentration reducing device 40.

  The air blowing mechanism 44 is a mechanism for taking air into the flow path 43 from the inlet 41 and causing the flow through the flow path 43. The blower mechanism 44 may be a blower fan provided in the flow path 43, for example. The air blowing control unit 46 controls the driving of the air blowing mechanism 44 in accordance with a control signal input from the control unit 13.

The carbon dioxide absorber 45 is an absorbent that absorbs part or all of the carbon dioxide in the air taken in by the blower mechanism 44. Although the kind of the carbon dioxide absorption part 45 is not specifically limited, For example, Li ₂ ZrO ₃ , LiFeO ₂ , LiNiO ₂ , or Li composite oxide such as LiSiO ₄ may be used. Alternatively, the carbon dioxide absorber 45 may be an amine aqueous solution or activated carbon.

  The carbon dioxide absorber 45 is provided in the flow path 43. As shown in FIG. 2, the carbon dioxide absorber 45 may be provided on the outlet 42 side of the air blowing mechanism 44, and provided on the inlet 41 side of the air blowing mechanism 44, contrary to the positional relationship shown in FIG. 2. May be. In any case, the air taken into the flow path 43 by the blower mechanism 44 passes through the carbon dioxide absorption part 45. In the air after passing through the carbon dioxide absorber 45, the carbon dioxide concentration is reduced as compared with the air before passing through the carbon dioxide absorber 45.

  In the present embodiment, the carbon dioxide control device 10 is described as a device separate from the human detection sensor 20, the carbon dioxide concentration sensor 30, the carbon dioxide concentration reduction device 40, and the storage unit 90. However, the carbon dioxide control device according to an aspect of the present disclosure may include one or more of the human detection sensor 20, the carbon dioxide concentration sensor 30, the carbon dioxide concentration reduction device 40, and the storage unit 90.

(CO2 concentration control method)
FIG. 3 is a flowchart showing a carbon dioxide concentration control method executed by the carbon dioxide control device 10.

  In the carbon dioxide control device 10, first, the detection unit 11 detects the person 200 existing in the space 100 by the human detection sensor 20 (S1, detection step). Next, the control part 13 determines whether the person detection sensor 20 detected the person 200 in the space 100 (S2). When the control unit 13 determines that the human detection sensor 20 has not detected the person 200 in the space 100 (NO in S2), the carbon dioxide control device 10 repeats the process from step S1 again.

  On the other hand, when the control unit 13 determines that the human detection sensor 20 has detected the person 200 in the space 100 (YES in S2), the carbon dioxide concentration acquisition unit 12 uses the carbon dioxide concentration sensor 30 to emit carbon dioxide in the space 100. The concentration of carbon is detected (S3). Further, the control unit 13 determines whether or not the carbon dioxide concentration in the space 100 is larger than a predetermined reference concentration (S4).

  When the control unit 13 determines that the carbon dioxide concentration in the space 100 is larger than the predetermined reference concentration (YES in S4), the control unit 13 operates the carbon dioxide concentration reducing device 40 (S5, carbon dioxide concentration adjusting step). . Specifically, the control unit 13 operates the blower mechanism 44. On the other hand, when the control unit 13 determines that the carbon dioxide concentration in the space 100 is equal to or lower than the predetermined reference concentration (NO in S4), the control unit 13 stops the operation of the carbon dioxide concentration reducing device 40 (S6). .

  If the carbon dioxide concentration reducing device 40 is operating when the determination in step S4 is YES, the control unit 13 does nothing in step S5. Similarly, even when the carbon dioxide concentration reducing device 40 is not operating when the determination in step S4 is NO, the control unit 13 does nothing in step S6.

  Thereafter, the detection unit 11 detects again the person 200 existing in the space 100 by the human detection sensor 20 (S7), and the control unit 13 determines again whether the human detection sensor 20 detects the person 200 in the space 100 ( S8). When the control unit 13 determines that the human detection sensor 20 detects the person 200 in the space 100 (YES in S8), the carbon dioxide control device 10 repeats the process from step S3 again. On the other hand, when the control unit 13 determines that the human detection sensor 20 has not detected the person 200 in the space 100 (NO in S8), the carbon dioxide control device 10 ends the process.

  Note that the carbon dioxide control device 10 may perform step S3 of measuring the concentration of carbon dioxide regardless of the determination result of step S2, that is, whether or not the person 200 exists in the space 100. . That is, the carbon dioxide control device 10 may perform step S <b> 5 for adjusting at least the concentration of carbon dioxide when the person 200 exists in the space 100.

  Further, the carbon dioxide control system 1 may include a switch in the space 100 for executing the processes from steps S <b> 3 to S <b> 7 instead of the human detection sensor 20. In this case, the detection unit 11 detects the person 200 by turning on / off the switch. When the switch is turned on, since it is considered that the person 200 existing in the space 100 has turned on the switch, the carbon dioxide control device 10 repeats the processes of steps S3 to S7. When the switch is turned off, it is considered that the person 200 is scheduled to leave the space 100, so the carbon dioxide control device 10 ends the process.

  However, when the carbon dioxide control device 10 includes the human detection sensor 20, the carbon dioxide control device 10 is based on the detection result of the human detection sensor 20 even when the person 200 leaves the space 100 without forgetting to turn off the switch. Ends the process. Therefore, it is preferable from the viewpoint of energy saving that the carbon dioxide control device 10 includes the human detection sensor 20.

(Experiment on the relationship between carbon dioxide concentration and workload)
An experiment was conducted on the relationship between carbon dioxide concentration in the space and the amount of work. In the experiment, five healthy adult boys were allowed to perform typing work. In common with the subjects, sufficient sleep time of the previous day was secured, and drinking was prohibited. The typing work is a work in which the subject similarly inputs a character string displayed on the screen of the personal computer using the keyboard. The typing time was 60 minutes, and the number of characters correctly input within the time (hereinafter referred to as the number of correct input characters) was defined as the workload.

  The subject performed typing in a constant temperature and humidity laboratory (width 2060 mm, depth 2080 mm, ceiling height 2700 mm) in which temperature, humidity, and carbon dioxide concentration can be arbitrarily set. The room temperature in the laboratory was 25 ° C. and the relative humidity was 50%. Further, the illuminance on the desk surface on which the subject performs the typing work is set to 750 lx. There were four conditions for the carbon dioxide concentration in the laboratory: 600 ppm, 1500 ppm, 3500 ppm, and 5000 ppm.

  The carbon dioxide concentration in the laboratory was adjusted by supplying carbon dioxide from the carbon dioxide cylinder into the laboratory at a constant flow rate.

  However, with respect to the condition for setting the carbon dioxide concentration to 5000 ppm, the carbon dioxide concentration in the laboratory was set to 600 ppm, and the carbon dioxide concentration was set to a pseudo 5000 ppm condition by causing the subject to wear a mask (surgical type). At this time, a space having a predetermined volume (air volume) was provided between the mask and the face of the subject, and the outer edge of the mask was brought into close contact with the face. The carbon dioxide concentration was calculated on the assumption that the air volume was 150 ml, the carbon dioxide concentration contained in the exhalation of the subject was 3.5%, and the leak rate of the mask was 50%.

  In one experiment, one subject entered a laboratory that was previously set and maintained at any of the above carbon dioxide concentrations, and after 30 minutes of adaptation time, 60 minutes of typing was performed. After completing the typing work, the subject rested for 15 minutes and then left the laboratory. In addition, a sufficient time interval was set between each experiment, and an experiment plan was designed and implemented in consideration of the experimental order not affecting the results of the typing work of the subjects as much as possible.

  FIG. 4 is a graph showing the relationship between the carbon dioxide concentration in the laboratory and the average value of the number of correct input characters. In FIG. 4, the horizontal axis represents the carbon dioxide concentration in the laboratory. The vertical axis measures the number of correct input characters for each subject under each carbon dioxide concentration condition, normalizes each measurement result for the number of correct input characters under the 600 ppm condition for each subject, This is the average of the subjects.

  As shown in FIG. 4, it was found that the average value of the number of correct input characters is significantly reduced particularly when the carbon dioxide concentration exceeds 3500 ppm. The broken line in FIG. 4 is a line where the average value of the number of correct input characters is 90%. Below this line, workability may be significantly impaired (the amount of work performed correctly) may be significantly impaired. For this reason, in order to improve the amount of work for the worker, it is understood that the carbon dioxide concentration in the vicinity of the worker is preferably set to 3500 ppm or less so that the average value of the number of correct input characters is 90% or more. It was.

  Further, as shown in FIG. 4, there is no significant difference in the average value of the ratio of the number of correct input characters between the case where the carbon dioxide concentration is 600 ppm and the case where it is 1500 ppm. For this reason, in order to improve the work amount of the worker, the carbon dioxide concentration in the vicinity of the worker is more preferably 1500 ppm or less. Although there is no significant difference in the average value of the variation rate of the number of correct input characters between the case where the carbon dioxide concentration is 600 ppm and the case where it is 1500 ppm, the carbon dioxide concentration is more preferably 600 ppm or more and 1500 ppm or less. I understood it.

(effect)
As described above, according to the carbon dioxide control method executed by the carbon dioxide control device 10, when the carbon dioxide concentration in the space 100 near the person 200 in the closed space is larger than a predetermined reference concentration, the carbon dioxide The density can be controlled to be equal to or lower than the reference density. The reference concentration is the concentration of carbon dioxide considering the work efficiency of the person 200. Therefore, according to the carbon dioxide control device 10, the working efficiency of the person 200 can be improved.

  More specifically, the carbon dioxide control device 10 can control the carbon dioxide concentration to be 3500 ppm or less when the carbon dioxide concentration in the space 100 is larger than 3500 ppm. By setting the carbon dioxide concentration in the space 100 to 3500 ppm or less, the work efficiency of the person 200 working in the space 100 is improved.

[Embodiment 2]
Other embodiments of the present disclosure are described below. For convenience of explanation, members having the same functions as those described in the above embodiment are given the same reference numerals, and the description thereof will not be repeated.

  FIG. 5 is a block diagram showing a configuration of the carbon dioxide control system 2 according to the present embodiment. As shown in FIG. 5, the carbon dioxide control system 2 includes an input device 50 and is different from the carbon dioxide control system 1 in that a carbon dioxide control device 10 </ b> A is provided instead of the carbon dioxide control device 10. The carbon dioxide control device 10 </ b> A includes an input receiving unit 14 in addition to the configuration included in the carbon dioxide control device 10.

  The input device 50 is an input device for receiving an input by a user for changing the reference density. The input device 50 may be a keyboard, a button, or a lever, for example. The input receiving unit 14 receives a user input from the input device 50 and causes the storage unit 90 to store a reference density corresponding to the input. The carbon dioxide concentration acquisition unit 12 determines whether or not the carbon dioxide concentration in the space 100 exceeds the reference concentration stored in the storage unit 90. Note that the user who performs input using the input device 50 may be the person 200 or another user.

  FIG. 6 is a flowchart showing a carbon dioxide control method executed by the carbon dioxide control device 10A. As shown in FIG. 6, in the carbon dioxide control method executed by the carbon dioxide control device 10A, steps S1 and S2 similar to the carbon dioxide control method executed by the carbon dioxide control device 10 are executed. After step S2, the input receiving unit 14 receives an input by the user for changing the reference density (S11, input receiving step). Thereafter, the carbon dioxide control device 10A executes steps S3 to S7 similar to the carbon dioxide control method executed by the carbon dioxide control device 10. The input receiving unit 14 may always receive an input for changing the reference density.

  In addition to the effect which the carbon dioxide control apparatus 10 show | plays, the carbon dioxide control apparatus 10A has the following effects. In general, there is an upper limit to the amount of carbon dioxide that can be absorbed by the carbon dioxide absorber 45. For this reason, in any of the carbon dioxide control systems 1 and 2, it is necessary to replace the carbon dioxide absorber 45 every time the operation time of the carbon dioxide concentration reducing device 40 reaches a certain time.

  In the carbon dioxide control device 10A, the user can change the reference concentration. For this reason, when the necessity for improving work efficiency is small, the operating time of the carbon dioxide concentration reducing device 40 can be shortened by increasing the reference concentration. Therefore, in the carbon dioxide control system 2 including the carbon dioxide control device 10 </ b> A, the frequency with which the carbon dioxide absorption unit 45 is replaced can be made lower than that with the carbon dioxide control system 1. Thereby, the increase in the running cost accompanying replacement | exchange of the carbon dioxide absorption part 45 can be suppressed.

[Embodiment 3]
Other embodiments of the present disclosure are described below.

  FIG. 7 is a block diagram illustrating a configuration of the carbon dioxide control system 3 according to the present embodiment. As shown in FIG. 7, the carbon dioxide control system 3 is different from the carbon dioxide control system 1 in that a carbon dioxide concentration reducing device 40 </ b> A is provided instead of the carbon dioxide concentration reducing device 40.

  FIG. 8 is a diagram illustrating a configuration of a carbon dioxide concentration reducing device 40 </ b> A included in the carbon dioxide control system 3. As shown in FIG. 8, the carbon dioxide concentration reducing device 40 </ b> A is different from the carbon dioxide concentration reducing device 40 in that it does not include the carbon dioxide absorption unit 45 (see FIG. 2). Further, the inlet 41 of the carbon dioxide concentration reducing device 40A communicates with the outside of the closed space so as to take in outside air. Therefore, in the carbon dioxide concentration reducing device 40 </ b> A, the outside air can be sent into the space 100 by operating the air blowing mechanism 44.

  Generally, the concentration of carbon dioxide contained in the outside air is about 400 ppm. Therefore, according to the carbon dioxide control system 3, by sending outside air into the space 100, the carbon dioxide concentration in the space 100 can be adjusted to a reference concentration (for example, 3500 ppm) or less so as not to reduce the working efficiency of the person 200. .

  The carbon dioxide control method executed by the carbon dioxide control device 10 included in the carbon dioxide control system 3 is as described in the first embodiment.

  In the carbon dioxide control system 3 of the present embodiment, the carbon dioxide concentration reducing device 40A does not include the carbon dioxide absorption unit 45. Therefore, compared with the carbon dioxide concentration reducing device 40 that needs to replace the carbon dioxide absorber 45, the user's labor is reduced.

[Embodiment 4]
Other embodiments of the present disclosure are described below.

  FIG. 9 is a block diagram showing a configuration of the carbon dioxide control system 4 according to the present embodiment. As shown in FIG. 9, the carbon dioxide control system 4 includes (i) a point provided with a temperature / humidity measuring unit 60, (ii) a point provided with a carbon dioxide concentration reducing device 40B instead of the carbon dioxide concentration reducing device 40A, and ( iii) It differs from the carbon dioxide control system 3 in that a carbon dioxide control device 10B is provided instead of the carbon dioxide control device 10. The carbon dioxide control device 10B is different from the carbon dioxide control device 10 in that a control unit 13B is provided instead of the control unit 13.

  When operating the carbon dioxide concentration reducing device 40B, the control unit 13B transmits a control signal for operating the air blowing mechanism 44 and the temperature / humidity adjusting unit 47 to the air blowing control unit 46B (described later).

  The temperature / humidity measuring unit 60 measures the temperature and humidity of the space 100. Specifically, the temperature / humidity measurement unit 60 includes a temperature sensor and a humidity sensor. The temperature sensor may be a thermistor thermometer, for example. The humidity sensor may be, for example, an electric hygrometer that measures humidity by changing the electrical characteristics of the hygroscopic agent. The temperature / humidity measurement unit 60 transmits the measured temperature and humidity to the control unit 13.

  FIG. 10 is a diagram illustrating a configuration of a carbon dioxide concentration reducing device 40B included in the carbon dioxide control system 4. As shown in FIG. 10, the carbon dioxide concentration reducing device 40 </ b> B is different from the carbon dioxide concentration reducing device 40 </ b> A in that it includes a ventilation control unit 46 </ b> B instead of the ventilation control unit 46 and further includes a temperature / humidity adjustment unit 47. In addition, the inlet 41 of the carbon dioxide concentration reducing device 40B communicates with the outside of the closed space, like the inlet 41 of the carbon dioxide concentration reducing device 40A.

  The temperature / humidity adjusting unit 47 adjusts the temperature and humidity of the outside air sent into the space 100. The temperature / humidity adjusting unit 47 is provided in the flow path 43. As shown in FIG. 10, the temperature / humidity adjusting unit 47 may be provided closer to the outlet 42 than the blower mechanism 44, and provided closer to the inlet 41 than the blower mechanism 44, contrary to the positional relationship shown in FIG. 10. May be.

  The air blow control unit 46 </ b> B controls the air blow mechanism 44 similarly to the air blow control unit 46 and further controls the temperature / humidity adjustment unit 47. Specifically, the air blowing control unit 46B receives data indicating the temperature and humidity of the space 100 from the control unit 13B, and the temperature and humidity so that the temperature and humidity of the outside air sent into the space 100 are close to those of the space 100. The adjustment unit 47 is controlled.

  FIG. 11 is a flowchart showing a carbon dioxide control method executed by the carbon dioxide control device 10B. Similarly to the carbon dioxide control device 10, the carbon dioxide control device 10B executes the processes of steps S1 to S5. In the carbon dioxide control device 10B, after step S5, the control unit 13B acquires the temperature and humidity of the space 100 from the temperature / humidity measurement unit 60 (S21). Furthermore, the control unit 13B controls the temperature / humidity adjustment unit 47 so that the temperature and humidity of the outside air sent into the space 100 are close to the temperature and humidity of the space 100 (S22). Thereafter, similarly to the carbon dioxide control device 10, the carbon dioxide control device 10B executes the processes of steps S7 and S8.

  In addition to the effect which the carbon dioxide control apparatus 10 has in the carbon dioxide control system 3, the carbon dioxide control apparatus 10B has the following effects. That is, the control unit 13B adjusts the temperature and humidity of the outside air sent into the space 100 so as to be close to the temperature and humidity of the space 100. Therefore, since the difference between the temperature and humidity of the space 100 and the temperature and humidity of the outside air sent in becomes small, the possibility that the person 200 feels uncomfortable due to the difference is reduced.

  Note that in one aspect of the present disclosure, the carbon dioxide control device 10B may further include the input receiving unit 14 as in the carbon dioxide control device 10A.

[Example of software implementation]
The control blocks (particularly the detection unit 11, the carbon dioxide concentration acquisition unit 12, the control units 13 and 13B, and the input reception unit 14) of the carbon dioxide control devices 10, 10A, and 10B are formed in an integrated circuit (IC chip) or the like. It may be realized by a logic circuit (hardware) or may be realized by software.

  In the latter case, the carbon dioxide control devices 10, 10 </ b> A, and 10 </ b> B include a computer that executes instructions of a program that is software that realizes each function. The computer includes, for example, at least one processor (control device) and at least one computer-readable recording medium storing the program. In the computer, the processor reads the program from the recording medium and executes the program, thereby achieving the object of the present disclosure. As the processor, for example, a CPU (Central Processing Unit) can be used. As the recording medium, a “non-temporary tangible medium” such as a ROM (Read Only Memory), a tape, a disk, a card, a semiconductor memory, a programmable logic circuit, or the like can be used. Further, a RAM (Random Access Memory) for expanding the program may be further provided. Further, the program may be supplied to the computer via any transmission medium (such as a communication network or a broadcast wave) that can transmit the program. Note that one aspect of the present disclosure can also be realized in the form of a data signal embedded in a carrier wave, in which the program is embodied by electronic transmission.

  The present disclosure is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the embodiments can be obtained by appropriately combining technical means disclosed in different embodiments. Are also included in the technical scope of the present disclosure. Furthermore, a new technical feature can be formed by combining the technical means disclosed in each embodiment.

10, 10A, 10B Carbon dioxide control device (carbon dioxide concentration control device)
11 detection unit 13, 13B control unit (carbon dioxide concentration adjustment unit)
100 spaces 200 people

Claims (4)

A carbon dioxide concentration control method for controlling the concentration of carbon dioxide in a space where a person exists, which is a control target,
A detection step of detecting a person present in the space;
(I) when the person is detected in the space in the detection step, and (ii) the concentration of carbon dioxide in the space is greater than a predetermined reference concentration considering the work efficiency of the person, the concentration is A carbon dioxide concentration adjusting step for reducing the concentration of carbon dioxide in the space so as to be equal to or lower than a predetermined reference concentration;
The carbon dioxide concentration control method characterized by including.   The carbon dioxide concentration control method according to claim 1, wherein the predetermined reference concentration is 600 ppm or more and 3500 ppm or less.   The carbon dioxide concentration control method according to claim 1, further comprising an input receiving step of receiving an input by a user for changing the predetermined reference concentration. A carbon dioxide concentration control device that controls the concentration of carbon dioxide in a space where a person exists, which is a control target,
A detection unit for detecting a person existing in the space;
(I) when the detection unit detects the person in the space, and (ii) the concentration of carbon dioxide in the space is higher than a predetermined reference concentration considering the work efficiency of the person, the concentration is A carbon dioxide concentration adjusting unit that reduces the concentration of carbon dioxide in the space so as to be equal to or lower than a predetermined reference concentration;
A carbon dioxide concentration control device comprising:

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