Air conditioning system, determination device, and determination method

Abstract

To provide a determination device for determining the introduction time and the introduction amount of outside air into an air-conditioned space.SOLUTION: The determination device 20 includes an acquisition unit 21 that acquires a predicted temperature of outside air in a predetermined prediction period, a number-of-people prediction unit 22 that predicts number-of-people information related to the number of people present in an air-conditioned space into which outside air is introduced in the prediction period, a carbon dioxide concentration prediction unit 24 that predicts a carbon dioxide concentration in the air-conditioned space in the prediction period using the predicted number-of-people information, and a determination unit 25 that determines an introduction time and an introduction amount of outside air into the air-conditioned space using the acquired predicted temperature of outside air and the predicted number of people. The determination unit 25 determines the introduction timing and the introduction amount of the outside air so that the maximum value of the carbon dioxide concentration in the prediction period becomes equal to or less than the threshold value and the thermal load of the air-conditioned space becomes lower.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a determination device that determines the timing of introducing outside air into an air-conditioned space, and an air-conditioning system that introduces outside air into an air-conditioned space in accordance with the result of the determination. [Background technology]

[0002] Conventionally, in an air conditioning system that conditions an air-conditioned space that has an opening to the outdoors, when the outdoor air temperature is on the target side of temperature adjustment relative to the temperature of the air-conditioned space, the air conditioning system has been controlled so that air flows into the air-conditioned space from the opening (see, for example, Patent Document 1). Such a method can achieve energy savings. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-115053 Summary of the Invention [Problem to be solved by the invention]

[0004] However, conventional air conditioning systems determine whether to introduce outside air based on the temperature difference between indoors and outdoors during control. This poses a problem of limited energy-saving effects. For example, conventional air conditioning systems introduce outside air so that the carbon dioxide concentration in the air-conditioned space does not exceed a threshold. Therefore, when the peak of the carbon dioxide concentration in the air-conditioned space coincides with the peak of the outdoor temperature, the air conditioning efficiency is reduced by introducing outside air into the air-conditioned space at the peak of the carbon dioxide concentration. For example, in commercial facilities, the carbon dioxide concentration often peaks during the daytime when the outdoor temperature is at its peak, making this problem even more pronounced.

[0005] The present invention has been made to solve the above-mentioned problems, and relates to a determination device that determines the timing and amount of energy-saving outside air introduction taking into account carbon dioxide concentration, and an air conditioning system that introduces outside air into an air-conditioned space based on the determination result. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, a determination device according to one aspect of the present invention comprises an acquisition unit that acquires a predicted temperature or predicted specific enthalpy of outside air during a specified prediction period; a number of people prediction unit that predicts number of people information regarding the number of people present in the air-conditioned space into which outside air is introduced during the prediction period; a carbon dioxide concentration prediction unit that predicts the carbon dioxide concentration in the air-conditioned space during the prediction period using the number of people information predicted by the number of people prediction unit; and a determination unit that determines the timing and amount of outside air to be introduced into the air-conditioned space using the predicted temperature or predicted specific enthalpy of the outside air acquired by the acquisition unit and the carbon dioxide concentration predicted by the carbon dioxide concentration prediction unit, wherein the determination unit determines the timing and amount of outside air to be introduced into the air-conditioned space so that the maximum value of the carbon dioxide concentration during the prediction period is below a threshold value and the thermal load of the air-conditioned space is lowered.

[0007] With this configuration, the timing and amount of outside air to be introduced can be determined using the predicted carbon dioxide concentration in the air-conditioned space. Therefore, for example, by introducing outside air with a lower thermal load into the air-conditioned space before the carbon dioxide concentration peaks, it is possible to achieve more energy-efficient introduction of outside air. Furthermore, by introducing such outside air into the air-conditioned space in advance, it is possible to keep the maximum carbon dioxide concentration in the air-conditioned space below a threshold value.

[0008] In addition, in a determination device according to one aspect of the present invention, the carbon dioxide concentration prediction unit may predict the carbon dioxide concentration by correcting a baseline carbon dioxide concentration corresponding to past measurement results for the air-conditioned space using number of people information predicted by the number of people prediction unit.

[0009] With this configuration, it becomes possible to predict the carbon dioxide concentration taking into account the characteristics of the air-conditioned space.

[0010] In addition, in a determination device according to one aspect of the present invention, the carbon dioxide concentration prediction unit may predict the carbon dioxide concentration by correcting a baseline carbon dioxide concentration having the same attributes as the prediction period using the number of people information predicted by the number of people prediction unit.

[0011] With this configuration, it is possible to predict the carbon dioxide concentration with higher accuracy by using a baseline carbon dioxide concentration that is appropriate for the prediction period.

[0012] In addition, the determination device according to one aspect of the present invention may further include a ventilation volume acquisition unit that acquires the ventilation volume of the air-conditioned space during the prediction period, and the carbon dioxide concentration prediction unit may predict the carbon dioxide concentration using the number of people information predicted by the number of people prediction unit and the ventilation volume acquired by the ventilation volume acquisition unit.

[0013] With this configuration, for example, even if the ventilation volume corresponding to the prediction period is different from the ventilation volume corresponding to the baseline carbon dioxide concentration, it becomes possible to predict the carbon dioxide concentration according to the ventilation volume corresponding to that prediction period.

[0014] In addition, in a determination device according to one aspect of the present invention, the carbon dioxide concentration prediction unit may predict the carbon dioxide concentration by correcting a baseline carbon dioxide concentration corresponding to past measurement results for the air-conditioned space using the number of people information predicted by the number of people prediction unit and the ventilation volume acquired by the ventilation volume acquisition unit.

[0015] With this configuration, it becomes possible to predict the carbon dioxide concentration taking into account the characteristics of the air-conditioned space.

[0016] In addition, in a determination device according to one aspect of the present invention, when the maximum value of the carbon dioxide concentration in the prediction period exceeds a threshold value, the determination unit may determine that the time to introduce outside air is the time closest to the time point at which the carbon dioxide concentration in the prediction period is maximum, within a period in which the predicted temperature or predicted specific enthalpy of the outside air acquired by the acquisition unit is within a predetermined range.

[0017] With this configuration, the timing of introducing outside air can be determined so as to reduce the heat load on the air-conditioned space.

[0018] In the determination device according to an aspect of the present invention, the number of people information may be a crowd density.

[0019] In addition, an air conditioning system according to one aspect of the present invention includes a determination device, an air conditioning device that introduces outside air into an air-conditioned space, and a control unit that controls the air conditioning device so that outside air is introduced into the air-conditioned space in accordance with the introduction timing and amount of outside air determined by the determination device.

[0020] With this configuration, the air conditioning system can introduce outside air while taking into account the carbon dioxide concentration.

[0021] In addition, a determination method according to one aspect of the present invention is a determination method processed using an acquisition unit, a number of people prediction unit, a carbon dioxide concentration prediction unit, and a determination unit, and includes the steps of: the acquisition unit acquiring a predicted temperature or predicted specific enthalpy of outside air for a specified prediction period; the number of people prediction unit predicting number of people information regarding the number of people present in the air-conditioned space into which outside air will be introduced during the prediction period; the carbon dioxide concentration prediction unit predicting the carbon dioxide concentration in the air-conditioned space during the prediction period using the number of people information predicted in the number of people information predicting step; and the determination unit determining the timing and amount of outside air to be introduced into the air-conditioned space using the predicted temperature or predicted specific enthalpy of outside air acquired in the step of acquiring the predicted temperature or predicted specific enthalpy of outside air and the carbon dioxide concentration predicted in the carbon dioxide concentration predicting step, wherein in the step of determining the timing and amount of outside air to be introduced, the timing and amount of outside air to be introduced are determined so that the maximum value of the carbon dioxide concentration during the prediction period is below a threshold and the heat load of the air-conditioned space is lowered. [Effects of the Invention]

[0022] According to an aspect of the present invention, an air conditioning system and a determination device can determine the timing and amount of outside air to be introduced using the predicted carbon dioxide concentration in the air-conditioned space. For example, by introducing outside air that has a lower thermal load into the air-conditioned space before the carbon dioxide concentration reaches its peak, it is possible to achieve a more energy-efficient introduction of outside air. Furthermore, by introducing such outside air into the air-conditioned space in advance, it is possible to keep the maximum carbon dioxide concentration in the air-conditioned space below a threshold value. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a schematic diagram showing the configuration of an air conditioning device according to an embodiment of the present invention; [Figure 2] FIG. 2 is a functional block diagram showing a configuration related to control of the air conditioning system according to the embodiment. [Figure 3] FIG. 10 is a diagram showing a change in predicted outside air temperature in the embodiment. [Figure 4] FIG. 10 is a diagram showing a change in the crowd density in the embodiment; [Figure 5] FIG. 10 is a diagram showing a change in ventilation volume in the same embodiment. [Figure 6] FIG. 10 is a diagram showing a change in carbon dioxide concentration in the embodiment. [Figure 7] FIG. 10 is a diagram for explaining prediction of carbon dioxide concentration in the embodiment. [Figure 8] A flowchart showing the operation of the determination device according to the embodiment. [Figure 9] FIG. 2 shows an example of the configuration of a computer system according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0024] A determination device, an air conditioning system including the determination device, and a determination method according to the present invention will be described below using embodiments. In the following embodiments, components and steps denoted by the same reference numerals are identical or equivalent, and repeated description may be omitted. The air conditioning system according to this embodiment predicts the carbon dioxide concentration during a predetermined prediction period using predicted number of people information regarding the number of people present in the air-conditioned space during that prediction period and the ventilation rate of the air-conditioned space during that prediction period, and determines the timing and amount of outside air to be introduced into the air-conditioned space using the carbon dioxide concentration and the predicted temperature or predicted specific enthalpy of the outside air.

[0025] FIG. 1 is a schematic diagram showing the configuration of an air conditioner 10 according to this embodiment, and FIG. 2 is a functional block diagram showing the configuration related to control of the air conditioning system 1 according to this embodiment. The air conditioning system 1 includes the air conditioner 10, a determination device 20, and a control unit 30, and may further include a duct 61 for supply air (SA) to the air-conditioned space 3 and a duct 62 for return air (RA) from the air-conditioned space 3, as necessary. The determination device 20 includes an acquisition unit 21, a number of occupants prediction unit 22, a ventilation rate acquisition unit 23, a carbon dioxide concentration prediction unit 24, a determination unit 25, an output unit 26, and a memory unit 27. The air-conditioned space 3 is a space to be air-conditioned by the air-conditioning system 1, particularly a space to be introduced with outside air. The air-conditioned space 3 is not particularly limited, and may be, for example, an office, a commercial facility, a store, a station, an airport, or an underground mall.

[0026] 1, the air conditioner 10 introduces outside air (OA) taken in through an outside air inlet 51 into the air-conditioned space 3. The air conditioner 10 may also adjust the temperature of the air supplied to the air-conditioned space 3, for example. In this embodiment, a case will be mainly described in which the air conditioner 10 both introduces outside air into the air-conditioned space 3 and adjusts the temperature of the air in the air-conditioned space 3.

[0027] For example, the air conditioner 10 may include fans 11 and 12, a coil 13, a return air duct 14a, an outside air introduction duct 14b, an exhaust air (EA) duct 14c, and dampers 15a to 15c provided in the ducts 14a to 14c, respectively. For example, one end of the exhaust air duct 14c may be connected to the return air duct 14a at a position between the damper 15a and the fan 12. Outside air is taken into the duct 14b through an outside air introduction port 51. The exhaust air is discharged from an exhaust air discharge port 52 via the duct 14c.

[0028] The blower 11 sends return air or outside air to the air-conditioned space 3. In addition, when the temperature or humidity of the air is adjusted by the coil 13, the adjusted air is sent to the air-conditioned space 3 by the blower 11.

[0029] The blower 12 exhausts the return air from the air-conditioned space 3 and / or sends it to the blower 11. The ratio of exhaust air to sending air to the blower 11 may be changed by adjusting the airflow rates of the dampers 15a and 15c, for example.

[0030] Coil 13 is a heat exchanger for adjusting the temperature of the air. Coil 13 may be supplied with cold water or hot water from heat source equipment 9 having, for example, a boiler or a refrigerator. When cooling is performed by air conditioner 10, cold water may be supplied to coil 13 from heat source equipment 9, and when heating is performed by air conditioner 10, hot water may be supplied to coil 13 from heat source equipment 9. Coil 13 may also adjust the humidity of the air, i.e., dehumidify, for example. In this case, cold water at a temperature equal to or lower than the dew point temperature of the air passing through coil 13 may be supplied to coil 13.

[0031] The volume of supply air supplied to the air-conditioned space 3 may be adjusted, for example, by the fan 11, or by a variable air volume (VAV) device provided in the duct 61 through which the supply air passes. When adjusting the volume of air by the fan 11, the air conditioner 10 may use a fan 11 that can adjust the volume of air, such as an inverter-controlled fan 11 or a fan 11 that uses a DC motor.

[0032] The dampers 15a to 15c may be, for example, motor dampers, and the air volume may be adjusted by the control unit 30. For example, by adjusting the air volumes of the dampers 15a and 15c, the proportion of the return air that is exhausted is changed. Also, for example, by adjusting the air volume of the damper 15b, the air volume of the outside air is changed. In this way, by adjusting the air volumes of the dampers 15a to 15c, the amount of outside air introduced into the air-conditioned space 3, the ventilation volume of the air-conditioned space 3, etc. may be adjusted.

[0033] The acquisition unit 21 acquires a predicted temperature or predicted specific enthalpy of the outdoor air for a predetermined prediction period. The predicted temperature or predicted specific enthalpy may be a predicted air temperature or predicted specific enthalpy at the location or area where the air-conditioned space 3 is located. The predicted temperature or predicted specific enthalpy acquired by the acquisition unit 21 corresponds to the prediction period. Preferably, this prediction period includes a time period suitable for taking outdoor air into the air-conditioned space 3. The prediction period may be a predetermined time period, such as 24 hours or 18 hours. The prediction period may be a time period equivalent to one day, such as 24 hours from midnight to 12:00 PM, or a partial time period of one day, such as 18 hours from 4:00 AM to 10:00 PM. The predicted outdoor air temperature acquired by the acquisition unit 21 preferably indicates a change in outdoor air temperature over time, as shown in FIG. 3, for example. The predicted outdoor air temperature may be a predicted outdoor air temperature for a predetermined time period, such as every hour or every 15 minutes. The same is true for other information that changes over time, such as the predicted specific enthalpy of the outside air.

[0034] The acquisition unit 21 may acquire the predicted outdoor air temperature and predicted specific enthalpy from, for example, the Japan Meteorological Agency or a private company that provides weather information. As an example, the acquisition unit 21 may acquire the predicted outdoor air temperature and predicted specific enthalpy at the location or region where the air-conditioned space 3 is located via a communication line such as the Internet. The specific enthalpy can be calculated using, for example, two values ​​from the dry-bulb temperature, the wet-bulb temperature, the relative humidity, and the absolute humidity. Therefore, as an example, the acquisition unit 21 may acquire two values ​​from the predicted dry-bulb temperature, the predicted wet-bulb temperature, the predicted relative humidity, and the predicted absolute humidity, and calculate the predicted specific enthalpy using the two acquired values. As another example, the acquisition unit 21 may acquire the predicted outdoor air temperature and predicted specific enthalpy by predicting the outdoor air temperature and humidity at the location where the air-conditioned space 3 is located using weather information such as past outdoor air temperatures at the location where the air-conditioned space 3 is located and weather information such as future weather in the region where the air-conditioned space 3 is located. In this embodiment, a case where the acquisition unit 21 acquires a predicted outside air temperature will be mainly described.

[0035] The number of people prediction unit 22 predicts number of people information regarding the number of people present in the air-conditioned space 3 during the prediction period. The number of people information may be, for example, information indicating the actual number of people present in the air-conditioned space 3, or information indicating the population density in the air-conditioned space 3. The population density can be calculated, for example, by dividing the number of people in the air-conditioned space 3 by the area of ​​the air-conditioned space 3. Note that because the area of ​​the air-conditioned space 3 is fixed, the number of people themselves and the population density are convertible information. Therefore, the number of people information may be information indicating either. In this embodiment, the case where the number of people information is the population density will be mainly described. It is preferable that the number of people information for the prediction period predicted by the number of people prediction unit 22 be information that indicates changes in the number of people information over time, such as the population density 102 shown in FIG. 4.

[0036] Based on a model that changes in the number of people present in a space have periodicity, such as a one-week cycle or a one-year cycle, the number-of-people prediction unit 22 may acquire number-of-people information for the prediction period, for example, by using the history of number-of-people information in the air-conditioned space 3. In this case, the number-of-people prediction unit 22 may acquire, as predicted number-of-people information, for example, number-of-people information for a time period corresponding to the prediction period in the air-conditioned space 3 one week or one year before the prediction period.

[0037] Furthermore, the number of people prediction unit 22 may predict the number of people information using, for example, a learning device, i.e., a learning model. The learning device used to predict the number of people information may be, for example, a learning device that receives attribute information related to a certain period as input and outputs number of people information for that period. By inputting attribute information related to the prediction period into this learning device, the number of people information in the air-conditioned space 3 corresponding to the prediction period will be output. This learning device may be, for example, the learning result of a neural network (NN), the learning result of a support vector machine (SVM) or support vector regression (SVR), or the learning result of other machine learning. The neural network may be, for example, a convolutional neural network (CNN), or other neural networks (for example, a neural network configured with a fully connected layer). In this embodiment, a case where the learning device is the learning result of a neural network will be mainly described.

[0038] The attribute information input to the learning device may include, for example, period information that is information about a period, weather information that is information about the weather, event information that is information about an event, or other information. Note that the weather information and event information are preferably information about the location of the air-conditioned space 3 or the vicinity of the air-conditioned space 3.

[0039] The period information may include, for example, a season indicating spring, summer, winter, autumn, etc., a month such as January or February, a day of the week such as Monday or Tuesday, information indicating whether it is a weekday or a holiday, or other information related to the period. Holidays may include, for example, Sundays, Saturdays, and public holidays. The number of people prediction unit 22 may obtain period information related to the prediction period from, for example, a calendar unit (not shown).

[0040] The weather information may include, for example, weather such as sunny, cloudy, or rainy, temperature, humidity, wind speed, sunshine hours, or other weather-related information. Because the prediction period is a future period, the weather information corresponding to the prediction period is predicted information. The weather information may be information indicating changes in weather, temperature, humidity, etc. over time. The number of people prediction unit 22 may obtain weather information related to the prediction period from, for example, a website of the Japan Meteorological Agency or from a sensor that obtains weather, temperature, etc.

[0041] The event information may include, for example, information about events inside the air-conditioned space 3, information about events outside the air-conditioned space 3, or other information about events. Events outside the air-conditioned space 3 are preferably events held near the air-conditioned space 3. The information about events inside the air-conditioned space 3 and information about events outside the air-conditioned space 3 may include, for example, whether or not an event is taking place, the scale of the event (e.g., large, medium, or small), and the type of event (e.g., fireworks display, festival, baseball game, soccer game, etc.). The number of people prediction unit 22 may obtain event information about the prediction period from, for example, a website or server on which information about events is posted, or by reading information manually entered by an administrator or the like.

[0042] The learning device is generated by learning using multiple pairs of training input information, which is attribute information for a predetermined period, and training output information, which is information about the number of people in the air-conditioned space 3 during that predetermined period. The predetermined period is preferably the same time period as the prediction period. Actual measurement results may be used as the attribute information that is the training input information and the number of people information that is the training output information. For example, the attribute information that is the training input information may include weather information near the air-conditioned space 3 during a certain period, period information corresponding to that period, and event information related to the air-conditioned space 3 during that period. Furthermore, number of people information corresponding to the number of people measured in the air-conditioned space 3 during that period may be used as the training output information. Furthermore, the training output information may be information indicating changes in the number of people information over time during a predetermined period. In this case, when attribute information corresponding to the prediction period is input to the learning device, number of people information corresponding to the time series of the prediction period is output.

[0043] The learning device may be stored in, for example, the storage unit 27. The learning device being stored in the storage unit 27 may mean, for example, that the learning device itself (e.g., a function that outputs a value in response to an input, a model of the learning result, etc.) is stored, or that information such as parameters required to configure the learning device is stored. Even in the latter case, the learning device can be configured using the information such as parameters, so that the learning device can be considered to be essentially stored in the storage unit 27. In this embodiment, the case where the learning device itself is stored in the storage unit 27 will be mainly described.

[0044] The number of people prediction unit 22 acquires attribute information corresponding to the prediction period and applies the acquired attribute information to a learning device to acquire a prediction result of the number of people information. The acquired prediction result of the number of people information corresponds to the prediction period and may indicate a change in the number of people information over time. In this way, the number of people prediction unit 22 can predict the number of people information for the prediction period using the learning device.

[0045] The ventilation rate acquisition unit 23 acquires the ventilation rate of the air-conditioned space 3 for the prediction period. The ventilation rate acquisition unit 23 may acquire the ventilation rate of the air-conditioned space 3 for the prediction period indicated by, for example, the operation plan of the air conditioner 10. In this case, the ventilation rate acquisition unit 23 may acquire the ventilation rate corresponding to the date of the prediction period from ventilation rates stored in association with the date. The ventilation rate for the prediction period acquired by the ventilation rate acquisition unit 23 is preferably one that allows changes in ventilation rate over time to be determined, such as the ventilation rate 202 shown in FIG. 5. The ventilation rate for the prediction period acquired by the ventilation rate acquisition unit 23 may, for example, be a ventilation rate that takes into account a morning purge or the like, or may not be such a rate.

[0046] The carbon dioxide concentration prediction unit 24 predicts the carbon dioxide concentration in the air-conditioned space 3 for the prediction period using the number of people information predicted by the number of people prediction unit 22 and the ventilation rate acquired by the ventilation rate acquisition unit 23. The carbon dioxide concentration prediction unit 24 may predict the carbon dioxide concentration for the prediction period by any method. For example, the carbon dioxide concentration may be predicted by correcting the baseline carbon dioxide concentration for the air-conditioned space 3 using the number of people information predicted by the number of people prediction unit 22 and the ventilation rate acquired by the ventilation rate acquisition unit 23. The baseline carbon dioxide concentration may be, for example, information indicating the change in carbon dioxide concentration for the air-conditioned space 3 during a time period corresponding to the prediction period. That is, the temporal length of the prediction period and the temporal length of the baseline carbon dioxide concentration may be the same. For example, if the prediction period is from midnight to 12:00 PM, it is preferable that the baseline carbon dioxide concentration also be information indicating the change in carbon dioxide concentration during that time period. The baseline carbon dioxide concentration is used as a reference for predicting the carbon dioxide concentration. The baseline carbon dioxide concentration may correspond to past measurement results for the air-conditioned space 3. That is, the baseline carbon dioxide concentration may be set based on past measurement results. The baseline carbon dioxide concentration is usually a result measured in the air-conditioned space 3, but may be, for example, an aggregate of multiple measurement results. The baseline carbon dioxide concentration obtained by integrating multiple measurement results may be, for example, an average value of the multiple measurement results.

[0047] The baseline carbon dioxide concentration is a reference carbon dioxide concentration that corresponds to the characteristics of the air-conditioned space 3. In theory, if the volume of the air-conditioned space 3, the number of people present in the air-conditioned space 3, the ventilation rate, and the like are known, the carbon dioxide concentration of the air-conditioned space 3 can be calculated without using past measurement results. However, in an actual air-conditioned space 3, air flows in and out through, for example, entrances and exits, and accordingly, the theoretically calculated carbon dioxide concentration may differ from the actual carbon dioxide concentration of the air-conditioned space 3. On the other hand, the baseline carbon dioxide concentration that corresponds to the carbon dioxide concentration measured in the air-conditioned space 3 corresponds to the characteristics of the air-conditioned space 3. Therefore, by predicting the carbon dioxide concentration of the air-conditioned space 3 by correcting the baseline carbon dioxide concentration, it becomes possible to predict the carbon dioxide concentration taking the characteristics of the air-conditioned space 3 into account, thereby improving the accuracy of the carbon dioxide concentration prediction.

[0048] The baseline carbon dioxide concentration is associated with the occupancy information and ventilation rate of the air-conditioned space 3 at the time the carbon dioxide concentration was measured. The occupancy information and ventilation rate associated with the baseline carbon dioxide concentration are referred to as reference occupancy information and reference ventilation rate, respectively. If the baseline carbon dioxide concentration is an integration of multiple measurement results, the reference occupancy information and reference ventilation rate corresponding to the baseline carbon dioxide concentration may also be an integration of multiple occupancy information and multiple ventilation rates. The integrated multiple occupancy information and multiple ventilation rates may be, for example, an average value of multiple occupancy information and multiple ventilation rates. The carbon dioxide concentration prediction unit 24 may obtain the carbon dioxide concentration for the prediction period by correcting the baseline carbon dioxide concentration based on, for example, a comparison result between the predicted occupancy information and the reference occupancy information (e.g., a ratio or difference between the two) and a comparison result between the acquired ventilation rate and the reference ventilation rate (e.g., a difference or ratio between the two). Details of this process will be described later.

[0049] The determination unit 25 determines the timing and amount of introduction of outside air into the air-conditioned space 3 using the predicted temperature or predicted specific enthalpy of the outside air acquired by the acquisition unit 21 and the carbon dioxide concentration predicted by the carbon dioxide concentration prediction unit 24. The determination unit 25 determines the timing and amount of introduction of outside air so that the maximum carbon dioxide concentration during the prediction period predicted by the carbon dioxide concentration prediction unit 24 is equal to or less than a threshold and the heat load of the air-conditioned space 3 is reduced. The carbon dioxide concentration threshold may be, for example, 1000 ppm or 950 ppm. Furthermore, by determining the timing of introduction of outside air so that the heat load of the air-conditioned space 3 is reduced compared to introducing outside air at a time different from the determined introduction time, for example, when the carbon dioxide concentration is at its maximum, the efficiency of air conditioning can be improved. When cooling is performed, the timing of introduction of outside air may be determined so that, for example, outside air with a lower temperature or a lower specific enthalpy is introduced into the air-conditioned space 3 than the outside air at the time when the carbon dioxide concentration is at its maximum. As an example, when the maximum carbon dioxide concentration during the prediction period predicted by the carbon dioxide concentration prediction unit 24 exceeds a threshold, the determination unit 25 may determine the time to introduce outdoor air to be a time that is closest to and before the time when the carbon dioxide concentration during the prediction period predicted by the carbon dioxide concentration prediction unit 24 will be at its maximum during the period in which the predicted temperature or predicted specific enthalpy of the outdoor air acquired by the acquisition unit 21 is within a predetermined range. When people are present in the air-conditioned space 3, the carbon dioxide concentration typically increases gradually over time. Therefore, even if a large amount of outdoor air is introduced significantly before the predicted peak of the carbon dioxide concentration, the effect of introducing the outdoor air may disappear by the time the carbon dioxide concentration peaks. Therefore, it is more effective to introduce outdoor air closer to the peak of the carbon dioxide concentration than before the peak. Note that the above-described introduction time may be determined when the time when the carbon dioxide concentration is at its maximum is not included in the period in which the predicted temperature or predicted specific enthalpy of the outdoor air acquired by the acquisition unit 21 is within a predetermined range. Furthermore, the determination unit 25 may determine the amount of outside air to be introduced at the introduction time so that the maximum value of the carbon dioxide concentration during the prediction period is equal to or less than a threshold value.The determination of the amount of outside air introduced into the air-conditioned space 3 may be, for example, a determination of the ventilation rate of the air-conditioned space 3. This is because the two are considered to be substantially the same. As an example, the additional amount of outside air introduced in a predetermined period (for example, 15 minutes) may be set to α(m 3 ), the ventilation volume (m 3 / h) is a value obtained by adding 4×α to the ventilation rate corresponding to the period acquired by the ventilation rate acquisition unit 23. Note that the amount of introduced outside air determined by the determination unit 25 may be, for example, an introduced rate added to the ventilation rate of the operation plan, that is, the value of α, or may be the amount of introduced outside air that includes the ventilation rate of the operation plan.

[0050] The predetermined range of the predicted temperature or predicted specific enthalpy of the outside air is preferably determined so that introducing outside air having a temperature or specific enthalpy within that range into the air-conditioned space 3 reduces the heat load of the air-conditioned space 3 more than introducing outside air having a temperature or specific enthalpy outside that range into the air-conditioned space 3. The predetermined range of the predicted temperature or predicted specific enthalpy may, for example, be determined in advance, or may be a value determined in relation to the target temperature or target specific enthalpy in the air-conditioned space 3. In the former case, the predetermined range of the predicted temperature may be determined, for example, to be 25°C or lower, or to be from 5°C to 25°C. In the latter case, that is, when the predetermined range is determined in relation to the target temperature, the predetermined range of the predicted temperature may be determined by substituting the target temperature obtained from the air conditioner 10 into a set range, such as (target temperature -2°C) or lower, or (target temperature -22°C) to (target temperature -2°C).

[0051] The determination unit 25 usually determines the timing of introducing outside air within the prediction period. Furthermore, when there are two or more peaks in the predicted carbon dioxide concentration that exceed the threshold, the determination unit 25 may first determine the timing and amount of introducing outside air so that the maximum peak is equal to or less than the threshold, and if there are further peaks that exceed the threshold, the determination unit 25 may further determine the timing and amount of introducing outside air so that the maximum peak at that time is equal to or less than the threshold, and repeat this process until there are no more peaks that exceed the threshold.

[0052] Note that, if the pre-introduction of outside air is not performed, the determination unit 25 does not need to determine the timing and amount of introduction of outside air as described above. That is, if the pre-introduction of outside air is performed, the determination unit 25 may determine the timing and amount of introduction of outside air so that the maximum carbon dioxide concentration during the prediction period is equal to or less than the threshold and the heat load of the air-conditioned space 3 is reduced, as described above. For example, if the acquired daily range of the predicted temperature of the outside air is smaller than the threshold, or if the acquired daily range of the predicted specific enthalpy of the outside air is smaller than the threshold, the determination unit 25 may determine not to introduce outside air in advance. The threshold for the daily range of the predicted temperature may be, for example, 2°C or 3°C. In this case, even if the pre-introduction of outside air into the air-conditioned space 3 before the carbon dioxide concentration peaks, energy conservation will not be promoted, or the degree of promotion will be very small. Furthermore, the decision unit 25 may decide not to introduce outside air in advance if, for example, the predicted temperature or the predicted specific enthalpy is within a predetermined range even when the predicted carbon dioxide concentration is at its maximum. This is because even if outside air is introduced when the carbon dioxide concentration is at its maximum, it is possible to introduce outside air whose temperature or specific enthalpy is within a predetermined range, i.e., outside air with a low thermal load on the air-conditioned space 3. In this way, when outside air is not introduced in advance, for example, the carbon dioxide concentration in the air-conditioned space 3 may be measured, and outside air may be introduced using real-time feedback control so that the measured carbon dioxide concentration does not exceed a threshold value.

[0053] Furthermore, the determination unit 25 may also determine not to introduce outside air in advance when the peak carbon dioxide concentration during the prediction period does not exceed the threshold. In this case, ventilation may be performed for the air-conditioned space 3 according to the ventilation rate acquired by the ventilation rate acquisition unit 23, i.e., the ventilation rate indicated by a predetermined operation plan. This is because, in this case, since the carbon dioxide concentration does not exceed the threshold, there is no need to introduce additional outside air in addition to the ventilation according to the operation plan.

[0054] The output unit 26 outputs the timing and amount of outside air to be introduced determined by the determination unit 25. This output may be, for example, transmitted to a predetermined device via a communication line, stored in a recording medium, or passed to another component. In this embodiment, a case will be mainly described in which the output unit 26 stores the determination result by the determination unit 25 in the storage unit 27. The output unit 26 may or may not include a device that performs output (e.g., a communication device, etc.). The output unit 26 may be realized by hardware, or may be realized by software such as a driver that drives such a device. For example, in a case in which the determination result is passed directly from the determination unit 25 to the control unit 30, the determination device 20 does not necessarily have to include the output unit 26.

[0055] As described above, the storage unit 27 stores the determination results made by the determination unit 25. The storage unit 27 may also store a learning device used to predict the number of people information, a baseline carbon dioxide concentration used to predict the carbon dioxide concentration, and the corresponding reference number of people information and reference ventilation volume.

[0056] The process by which information is stored in the storage unit 27 is not important. For example, information may be stored in the storage unit 27 via a recording medium, or information transmitted via a communication line or the like may be stored in the storage unit 27, or information input via an input device may be stored in the storage unit 27. Information may also be accumulated in the storage unit 27 by the output unit 26. The storage unit 27 is preferably realized by a non-volatile recording medium, but may also be realized by a volatile recording medium. The recording medium may be, for example, a semiconductor memory or a magnetic disk.

[0057] The control unit 30 controls the air conditioner 10 to introduce outside air into the air-conditioned space 3 according to the introduction timing and introduction amount of outside air determined by the determination unit 25. As an example, the control unit 30 may control the air conditioner 10 so that the ventilation rate according to the operation plan of the air conditioner 10 is changed according to the introduction timing and introduction amount of outside air, i.e., ventilation is performed. Note that if the determination unit 25 does not determine the introduction timing or introduction amount of outside air, the control unit 30 may control the air conditioner 10 to change the ventilation rate in real time so that the current carbon dioxide concentration measured in the air-conditioned space 3 does not exceed a threshold, or may control the air conditioner 10 so that ventilation is performed in the air-conditioned space 3 according to the ventilation rate that is a predetermined operation plan. In the former case, the control unit 30 may control the air conditioner 10 so that when the current carbon dioxide concentration in the air-conditioned space 3 does not exceed the threshold, ventilation is performed according to the ventilation volume in the operation plan, and when the current carbon dioxide concentration exceeds the threshold, ventilation is performed by increasing the ventilation volume until the current carbon dioxide concentration becomes equal to or less than the threshold, and after the current carbon dioxide concentration becomes equal to or less than the threshold, ventilation is performed according to the ventilation volume in the operation plan.

[0058] Next, an example of a process for predicting the carbon dioxide concentration and a process for determining the timing and amount of outside air to be introduced will be described. In this example, the baseline carbon dioxide concentration is the baseline carbon dioxide concentration 301 shown in Fig. 6, and the corresponding reference number of people information and reference ventilation rate are the reference person density 101 shown in Fig. 4 and the reference ventilation rate 201 shown in Fig. 5, respectively.

[0059] Also, assume that the person density, which is the number of people information predicted by the number of people prediction unit 22, is the person density 102 shown in Fig. 4, and the ventilation volume acquired by the ventilation volume acquisition unit 23 is the ventilation volume 202 shown in Fig. 5. Note that in Fig. 5, multiple ventilation volumes are slightly shifted so that they can be distinguished, but in reality, the multiple ventilation volumes overlap at some time.

[0060] In the baseline carbon dioxide concentration 301 shown in FIG. 6, the minimum value is usually considered to be the carbon dioxide concentration of the outdoor air. Here, the carbon dioxide concentration of the outdoor air is assumed to be 400 ppm. In addition, in the simplified model, the portion of the baseline carbon dioxide concentration 301 that exceeds the minimum value is considered to increase linearly according to the number of people present in the air-conditioned space 3. As a result, the carbon dioxide concentration (ppm) at a certain point in time is calculated based on the predicted occupancy density (people / m) at that point in time. 2 ), the reference population density at that time (people / m 2 ), the baseline carbon dioxide concentration (ppm) at that time, the carbon dioxide concentration of the outside air (= 400 ppm), etc., can be used to calculate the carbon dioxide concentration as follows: In this way, the carbon dioxide concentration prediction unit 24 may predict the carbon dioxide concentration according to the predicted human density, for example, using the ratio between the predicted human density and the reference human density. Carbon dioxide concentration = (predicted population density) x (baseline carbon dioxide concentration - 400) / (baseline population density) + 400

[0061] Note that the carbon dioxide concentration can be calculated using the above formula only during time periods when the reference pedestrian density is not 0. During time periods when the reference pedestrian density is 0, if the predicted pedestrian density is 0, the carbon dioxide concentration may be the carbon dioxide concentration of the outside air, and if the predicted pedestrian density is not 0, the carbon dioxide concentration may be the value obtained by multiplying the predicted pedestrian density by a predetermined coefficient and adding the carbon dioxide concentration of the outside air to the value. Also, the first term on the right side of the above formula may be multiplied by a predetermined coefficient close to 1. This coefficient may be determined, for example, using past measurements.

[0062] In this way, the determination unit 25 can calculate the carbon dioxide concentration at each point in time or each time interval during the prediction period using the predicted person density for the prediction period, the reference person density, the baseline carbon dioxide concentration, etc. The carbon dioxide concentration obtained in this way is assumed to be the carbon dioxide concentration 302 shown in Fig. 6. This carbon dioxide concentration 302 is obtained by correcting the baseline carbon dioxide concentration 301 using the person density, which is the predicted number of people information.

[0063] In addition, the volume of air ventilated in the air-conditioned space 3 is A (m 3 ), the carbon dioxide concentration in the air-conditioned space 3 before ventilation is C (ppm), and the volume of the air-conditioned space 3 is D (m 3 ), the carbon dioxide concentration in the air-conditioned space 3 after ventilation is expressed by the following formula. Here, too, the carbon dioxide concentration of the outside air introduced into the air-conditioned space 3 by ventilation is assumed to be 400 ppm. Furthermore, in actual ventilation, the air in the air-conditioned space 3 is gradually replaced, but in the following formula, the capacity A (m 3 The carbon dioxide concentration after ventilation is calculated using a simple model in which the carbon dioxide concentration of the air in the room changes from C (ppm) to 400 ppm in one go. Carbon dioxide concentration after ventilation = ((DA) × C + A × 400) / D

[0064] Therefore, at time t k Carbon dioxide concentration C in air-conditioned space 3 k is the time t k-1Carbon dioxide concentration C in air-conditioned space 3 k-1 Using the above, it can be calculated as follows: C k =((DA k-1 )×C k-1 +A k-1 ×400) / D+β k-1 =(D×C k-1 +A k-1 ×(400-C k-1 )) / D+β k-1

[0065] In the above equation, k is an integer index indicating time, and time t k The larger k is, the later the time point is. k-1 is the time t k-1 From time t k is the volume of air ventilated in the conditioned space 3 up to β k-1 (ppm) is the time t k-1 From time t k This is the increase in carbon dioxide concentration according to the carbon dioxide generated in the air-conditioned space 3 up to that point.

[0066] Next, at time t k-1 From time t k The volume of air ventilated up to k-1 From A k-1 +α k-1 It is assumed that α k-1 (m 3 ) is the change in the volume of ventilated air, and is, for example, a value corresponding to the difference between the acquired ventilation volume and the reference ventilation volume. For example, if the ventilation volume is the volume of air ventilated per unit time, α k-1 (m 3 ) is the difference between the ventilation volume and the reference ventilation volume multiplied by the time t k-1 From time t k The value may be multiplied by the time length t when the volume of ventilated air changes. k Carbon dioxide concentration C in air-conditioned space 3 M k is the time t k-1The carbon dioxide concentration C in the conditioned space 3 when the volume of ventilated air changes M k-1 Using the above, it can be calculated as follows: C M k =(D×C M k-1 +(A k-1 +α k-1 )×(400-C M k-1 )) / D+β k-1 =(D×C M k-1 +(A k-1 +α k-1 )×(400-C M k-1 )) / D +C k -(D×C k-1 +A k-1 ×(400-C k-1 )) / D

[0067] In this way, the carbon dioxide concentration prediction unit 24 may predict the carbon dioxide concentration according to the acquired ventilation volume, for example, by using the difference between the acquired ventilation volume and the reference ventilation volume. k etc. and C M k The relationship between these is shown in FIG. 7, for example. k 6 corresponds to the carbon dioxide concentration 302 shown in Fig. 6. Therefore, when the ventilation volume changes from the reference ventilation volume 201 corresponding to the baseline carbon dioxide concentration to the ventilation volume 202 acquired by the ventilation volume acquisition unit 23, the carbon dioxide concentration prediction unit 24 calculates a corresponding α k-1 and C indicated by the carbon dioxide concentration corrected using predicted human density. k By using the above formula, the carbon dioxide concentration C after changing the ventilation rate can be calculated. M k can be calculated in order from the time when the change in the volume of ventilated air is 0. That is, C M N =C N Time t NFrom the above, the carbon dioxide concentration C after changing the ventilation rate in time order M k It is possible to calculate the following. The carbon dioxide concentration calculated in this way, taking into account the ventilation rate acquired by the ventilation rate acquisition unit 23, is assumed to be carbon dioxide concentration 303 shown in Fig. 6. In other words, carbon dioxide concentration 303 is the carbon dioxide concentration of the prediction result obtained by correcting the baseline carbon dioxide concentration using the predicted number of people information and the acquired ventilation rate.

[0068] The determination unit 25 determines whether the maximum value of the predicted carbon dioxide concentration 303 exceeds the threshold value TH2. As described above, the threshold value TH2 may be, for example, 950 ppm or 1000 ppm. If the maximum value of the predicted carbon dioxide concentration 303 exceeds the threshold value TH2, as shown in FIG. 6, the determination unit 25 may determine the time to introduce outside air to be a time that is closest to and before the time when the predicted carbon dioxide concentration 303 reaches its maximum during a period in which the predicted outside air temperature acquired by the acquisition unit 21 is within a predetermined range. For example, in the case where the acquired predicted temperature is as shown in FIG. 3 and the predetermined range is a range in which the predicted temperature is lower than the threshold value TH1, the period before time T1 is the period in which the acquired predicted outside air temperature is within the predetermined range. In this case, the determination unit 25 determines the time T1, which is a time before the time when the predicted carbon dioxide concentration 303 will be at its maximum and is closest to the time when the predicted carbon dioxide concentration 303 will be at its maximum, as the time to introduce outside air. The time to introduce outside air may include time T1, but here, as an example, the time to introduce outside air is determined so that the end of the time to introduce outside air is time T1. Therefore, as with the ventilation volume 203 shown in FIG. 5, the time just before time T1 is determined as the time to introduce outside air to increase the ventilation volume. Note that, although the ventilation volume 203 in FIG. 5 indicates that the amount of outside air to be introduced has also been determined, the amount of outside air to be introduced has not yet been determined at this point.

[0069] Next, the determination unit 25 determines the amount of outside air to be introduced. Specifically, the determination unit 25 may gradually increase the amount of outside air to be introduced at the time of introducing outside air until the maximum value of the carbon dioxide concentration in the air-conditioned space 3 becomes equal to or less than the threshold value TH2. The determination unit 25 may, for example, determine the amount of outside air to be introduced by setting a predetermined volume γ(m 3 ), and each time the introduction amount is increased, the carbon dioxide concentration prediction unit 24 calculates the carbon dioxide concentration using the ventilation rate corresponding to the increased introduction amount. The determination unit 25 may then determine the introduction amount of outside air when the maximum carbon dioxide concentration corresponding to the increased introduction amount becomes equal to or less than the threshold value TH2 as the final introduction amount of outside air. The carbon dioxide concentration whose maximum value becomes equal to or less than the threshold value TH2 is assumed to be the carbon dioxide concentration 304 shown in FIG. 6. The ventilation rate corresponding to the determined introduction amount of outside air is assumed to be the ventilation rate 203 shown in FIG. 5. The ventilation rate 203 is the same as the ventilation rate 202 except that the ventilation rate increases immediately before time T1. Note that there is usually an upper limit to the ventilation rate. Therefore, for example, if the maximum carbon dioxide concentration does not become equal to or less than the threshold value TH2 even when the ventilation rate at a certain introduction period is increased to the upper limit, the duration of that introduction period may be extended.

[0070] Next, the operation of the determination device 20 will be described with reference to the flowchart of Fig. 8. In this flowchart, the case where a predicted outside air temperature is acquired will be described.

[0071] (Step S101) The acquisition unit 21 acquires a predicted outdoor temperature corresponding to a prediction period.

[0072] (Step S102) The determination unit 25 determines whether the daily range of the predicted outdoor air temperature acquired in step S101 exceeds a threshold. If the daily range of the predicted outdoor air temperature exceeds the threshold, the process proceeds to step S103; if not, the process ends without determining the timing or amount of outdoor air introduction. If the timing or amount of outdoor air introduction has not been determined, for example, when the carbon dioxide concentration in the air-conditioned space 3 exceeds a threshold, additional outdoor air may be introduced to control the carbon dioxide concentration to be below the threshold.

[0073] (Step S103) The number of people prediction unit 22 predicts the number of people information in the air-conditioned space 3 corresponding to the prediction period.

[0074] (Step S104) The ventilation rate acquisition unit 23 acquires the ventilation rate of the air-conditioned space 3 corresponding to the prediction period.

[0075] (Step S105) The carbon dioxide concentration prediction unit 24 predicts the carbon dioxide concentration in the air-conditioned space 3 corresponding to the prediction period using the number of people information in the air-conditioned space 3 predicted in step S103 and the ventilation volume of the air-conditioned space 3 obtained in step S104.

[0076] (Step S106) The determination unit 25 determines whether the maximum value of the carbon dioxide concentration acquired in step S105 exceeds a threshold value. If the maximum value exceeds the threshold value, the process proceeds to step S107. If the maximum value does not exceed the threshold value, the process ends without determining the timing or amount of introduction of outside air. This is because if the maximum value of the carbon dioxide concentration does not exceed the threshold value, there is no need to introduce additional outside air.

[0077] (Step S107) The determination unit 25 determines the timing for introducing outside air so as to reduce the heat load of the air-conditioned space 3 during the prediction period. As an example, the determination unit 25 may identify a time before and closest to the time when the carbon dioxide concentration reaches its maximum value during the period when the predicted outside air temperature acquired in step S101 is equal to or lower than the threshold value, and determine the identified time as the introduction time.

[0078] (Step S108) The determination unit 25 determines the amount of outside air to be introduced so that the maximum value of the carbon dioxide concentration in the air-conditioned space 3 during the prediction period becomes equal to or less than a threshold value. As an example, the determination unit 25 may gradually increase the amount of outside air to be introduced at the time when the outside air is introduced, and determine the amount of outside air to be introduced when the maximum value of the carbon dioxide concentration corresponding to that amount of outside air to be introduced becomes equal to or less than a threshold value as the final amount of outside air to be introduced. Then, the series of processes for determining the time and amount of outside air to be introduced ends. The determined time and amount of outside air to be introduced may be stored in the memory unit 27 by the output unit 26, for example.

[0079] In the flowchart of FIG. 8 , even when the predicted carbon dioxide concentration reaches its maximum, if the predicted temperature and predicted specific enthalpy are within a predetermined range, it may be determined not to introduce outside air in advance, and the timing and amount of introduction of outside air may not be determined. The order of the processes in the flowchart of FIG. 8 is merely an example, and the order of the steps may be changed as long as similar results are obtained. For example, the number of people information may be predicted after the ventilation rate is acquired. Although not included in the flowchart of FIG. 8 , the control unit 30 of the air conditioning system 1 controls the air conditioner 10 to introduce outside air into the air-conditioned space 3 according to the determined timing and amount of introduction of outside air. Although not included in the flowchart of FIG. 8 , the air conditioner 10 may adjust the temperature of the air supplied to the air-conditioned space 3 as appropriate. This temperature adjustment may adjust the temperature of the air in the air-conditioned space 3 to a desired temperature. The air temperature adjustment may be performed, for example, simultaneously with the introduction of outside air or separately from the introduction of outside air.

[0080] Next, the operation of the air conditioning system 1 according to this embodiment will be described using a specific example. In this specific example, the prediction period is 24 hours from midnight to 12:00 PM, and the carbon dioxide concentration for a day in the prediction period is predicted at 10:00 PM on the day before the day corresponding to the prediction period, and the timing and amount of outside air to be introduced are determined using this.

[0081] At 10:00 PM, the acquisition unit 21 acquires the predicted temperature for the prediction period, which is the following day, and passes it to the determination unit 25 (step S101). The determination unit 25 may store the predicted temperature in a recording medium (not shown) or the memory unit 27. The acquired predicted temperature is the one shown in FIG. 3, and it is assumed that the daily temperature difference exceeds the threshold (step S102). Then, the determination unit 25 passes instructions to the number of people prediction unit 22 and the ventilation volume acquisition unit 23 to acquire number of people information and ventilation volume, respectively, via paths (not shown).

[0082] Upon receiving an instruction to acquire the number of people information, the number of people prediction unit 22 acquires attribute information related to the air-conditioned space 3 for the next day. As described above, this attribute information may include period information, weather information, and event information. The number of people prediction unit 22 then applies the acquired attribute information to a learning device stored in the memory unit 27 to acquire the person density, which is the number of people information related to the air-conditioned space 3 for the next day, which is the output from the learning device, and passes this to the carbon dioxide concentration prediction unit 24 (step S103). The person density acquired in this manner is assumed to be the person density 102 shown in FIG. 4. The carbon dioxide concentration prediction unit 24 may store the received person density in a recording medium (not shown) or the memory unit 27.

[0083] Furthermore, upon receiving an instruction to acquire the ventilation volume, the ventilation volume acquisition unit 23 acquires the operation plan for the next day of the air conditioner 10 from a recording medium, a server, or the like that stores the operation plan, and passes it to the carbon dioxide concentration prediction unit 24 (step S104). The ventilation volume acquired in this manner is assumed to be the ventilation volume 202 shown in Fig. 5. The carbon dioxide concentration prediction unit 24 may store the received ventilation volume in a recording medium, memory unit 27, or the like (not shown).

[0084] Thereafter, the carbon dioxide concentration prediction unit 24 obtains the carbon dioxide concentration for the air-conditioned space 3 for the next day by correcting the baseline carbon dioxide concentration 301 shown in Fig. 6 as described above using the reference person density 101 shown in Fig. 4 that corresponds to the baseline carbon dioxide concentration 301 and the predicted person density 102 shown in Fig. 4. The carbon dioxide concentration obtained in this manner is assumed to be the carbon dioxide concentration 302 shown in Fig. 6. The carbon dioxide concentration prediction unit 24 may store the obtained carbon dioxide concentration in a recording medium (not shown) or the memory unit 27.

[0085] Furthermore, the carbon dioxide concentration prediction unit 24 corrects the carbon dioxide concentration 302 as described above using the reference ventilation rate 201 shown in Fig. 5, which corresponds to the baseline carbon dioxide concentration 301, and the acquired ventilation rate 202 shown in Fig. 5, to acquire the carbon dioxide concentration for the air-conditioned space 3 for the next day, and passes this to the determination unit 25 (step S105). The carbon dioxide concentration acquired in this manner is assumed to be the carbon dioxide concentration 303 shown in Fig. 6. The determination unit 25 may store the received carbon dioxide concentration in a recording medium, memory unit 27, or the like (not shown).

[0086] The determination unit 25 determines whether the received maximum value of the carbon dioxide concentration 303 exceeds the threshold value TH2 (step S106). In this case, as shown in Fig. 6, the maximum value of the carbon dioxide concentration 303 exceeds the threshold value TH2, so the determination unit 25 determines the period during which the predicted temperature for the next day is equal to or lower than the threshold value TH1, that is, the period before time T1, which is before the time when the carbon dioxide concentration 303 reaches its maximum and includes time T1, which is the period closest to the time when the carbon dioxide concentration 303 reaches its maximum, as the time to introduce outside air (step S107). Note that in this specific example, time T1 is the end period, and a period of a predetermined length is determined as the time to introduce outside air.

[0087] Furthermore, the determination unit 25 causes the carbon dioxide concentration prediction unit 24 to calculate the carbon dioxide concentration using the increased ventilation volume each time the ventilation volume at the determined time point for introducing outside air is increased from the ventilation volume 202. The increase in the ventilation volume at the time point for introducing outside air and the calculation of the carbon dioxide concentration using the increased ventilation volume are repeated until the maximum value of the calculated carbon dioxide concentration becomes equal to or less than the threshold value TH2. When the calculated maximum value of the carbon dioxide concentration becomes equal to or less than the threshold value TH2, the determination unit 25 sets the ventilation volume at that time point for introducing outside air as the final ventilation volume (step S108). In this manner, the amount of introduced outside air is determined. The ventilation volume corresponding to the determined amount of introduced outside air is assumed to be the ventilation volume 203 shown in FIG. 5. The determination unit 25 then passes the ventilation volume 203, which indicates the time point for introducing outside air and the amount of introduced outside air, to the output unit 26. The output unit 26 then stores the received ventilation volume 203 in the storage unit 27.

[0088] On the following day, the control unit 30 reads out the ventilation rate 203 stored in the memory unit 27 and controls the air conditioner 10 to introduce outside air into the air-conditioned space 3, i.e., to ventilate the air-conditioned space 3, according to the ventilation rate 203. In this way, by introducing outside air in advance so as to lower the heat load of the air-conditioned space 3 before the carbon dioxide concentration in the air-conditioned space 3 peaks, it is possible to prevent the carbon dioxide concentration in the air-conditioned space 3 from exceeding the threshold value TH2, increase the efficiency of air conditioning, and promote energy conservation.

[0089] As described above, the determination device 20 and air conditioning system 1 according to this embodiment can determine the timing and amount of introduction of outside air using the predicted carbon dioxide concentration in the air-conditioned space 3. Therefore, outside air can be introduced before the carbon dioxide concentration peaks so that the carbon dioxide concentration in the air-conditioned space 3 does not exceed the threshold. Furthermore, outside air can be introduced in advance to reduce the heat load of the air-conditioned space 3, thereby promoting energy conservation. Furthermore, the carbon dioxide concentration prediction unit 24 predicts the carbon dioxide concentration in the air-conditioned space 3 during the prediction period using the baseline carbon dioxide concentration, thereby making it possible to predict the carbon dioxide concentration according to the characteristics of the air-conditioned space 3.

[0090] Furthermore, by predicting the carbon dioxide concentration using the predicted number of people information, it is possible to make a more accurate prediction of the carbon dioxide concentration according to the predicted number of people in the air-conditioned space 3. Furthermore, by predicting the carbon dioxide concentration also using the acquired ventilation rate, it becomes possible to predict the carbon dioxide concentration according to the ventilation rate for the prediction period, even if, for example, the ventilation rate for the air-conditioned space 3 for the prediction period is different from the ventilation rate corresponding to the baseline carbon dioxide concentration, and it becomes possible to make a more accurate prediction of the carbon dioxide concentration.

[0091] In this embodiment, the case where the carbon dioxide concentration in the air-conditioned space 3 during the prediction period is predicted using the baseline carbon dioxide concentration has been mainly described, but this is not necessarily the case. As described above, the carbon dioxide concentration prediction unit 24 may predict the carbon dioxide concentration by calculating the carbon dioxide concentration in the air-conditioned space 3 using the volume of the air-conditioned space 3, headcount information regarding the number of people present in the air-conditioned space 3, the ventilation rate of the air-conditioned space 3, etc.

[0092] Furthermore, in the present embodiment, the case where the ventilation rate of the air-conditioned space 3 during the prediction period is acquired and used to predict the carbon dioxide concentration in the air-conditioned space 3 during the prediction period has been mainly described, but this is not necessarily the case. For example, if the ventilation rate of the air-conditioned space 3 is always constant, it is not necessary to acquire the ventilation rate. In this case, the determination device 20 may not be equipped with the ventilation rate acquisition unit 23. Furthermore, the carbon dioxide concentration prediction unit 24 may predict the carbon dioxide concentration in the air-conditioned space 3 during the prediction period using predicted number of people information without using the ventilation rate. For example, the carbon dioxide concentration prediction unit 24 may predict the carbon dioxide concentration using the number of people information predicted by the number of people prediction unit 22, or may predict the carbon dioxide concentration by correcting the baseline carbon dioxide concentration for the air-conditioned space 3 using the number of people information predicted by the number of people prediction unit 22. As an example, if the ventilation rate does not change, the carbon dioxide concentration resulting from correcting the baseline carbon dioxide concentration using the acquired number of people information becomes the carbon dioxide concentration in the air-conditioned space 3 during the prediction period. Therefore, the determination unit 25 may use the carbon dioxide concentration predicted in this way to determine the timing and amount of outside air to be introduced.

[0093] Furthermore, in the present embodiment, a case has been described in which only one baseline carbon dioxide concentration exists and is used to predict the carbon dioxide concentration in the air-conditioned space 3 for the prediction period, but this is not necessarily the case. There may be multiple baseline carbon dioxide concentrations for each attribute of the period corresponding to the baseline carbon dioxide concentration. In this case, the carbon dioxide concentration prediction unit 24 may predict the carbon dioxide concentration in the air-conditioned space 3 for the prediction period by correcting, from the multiple baseline carbon dioxide concentrations, the baseline carbon dioxide concentration having the same attribute as the prediction period using the number of people information predicted by the number of people prediction unit 22, or by correcting using the number of people information predicted by the number of people prediction unit 22 and the ventilation rate acquired by the ventilation rate acquisition unit 23.

[0094] More specifically, the storage unit 27 may store multiple pieces of correspondence information associating baseline carbon dioxide concentrations with attribute information indicating attributes of the corresponding time periods. The carbon dioxide concentration prediction unit 24 may then acquire attribute information for the prediction period and predict the carbon dioxide concentration in the air-conditioned space 3 for the prediction period using the baseline carbon dioxide concentrations associated with the acquired attribute information. The attribute information may include, for example, period information, weather information, and event information, as described above. The period information, weather information, and event information are as described above, and their description will be omitted. It is believed that the change over time in the carbon dioxide concentration in the air-conditioned space 3 varies depending on the season, whether it is a weekday or a holiday, the weather, the temperature, the presence or absence of an event, and so on. Therefore, by using the baseline carbon dioxide concentration corresponding to the attribute information for the prediction period, the carbon dioxide concentration in the air-conditioned space 3 for the prediction period can be predicted with higher accuracy.

[0095] Furthermore, in the present embodiment, when predicting the carbon dioxide concentration in the air-conditioned space 3 for the prediction period using the baseline carbon dioxide concentration, the baseline carbon dioxide concentration is corrected using the predicted occupancy information and the acquired ventilation rate using a calculation formula corresponding to a predetermined model as described above. However, this is not necessarily the case. For example, the carbon dioxide concentration in the air-conditioned space 3 may also be measured when the occupancy information and ventilation rate deviate from the reference occupancy information and reference ventilation rate corresponding to the baseline carbon dioxide concentration. Using the measurement results, a correspondence relationship between the deviation of the occupancy information from the reference occupancy information and the deviation of the ventilation rate from the reference ventilation rate and the corresponding deviation in the baseline carbon dioxide concentration may be obtained in advance. When the occupancy information is predicted and the ventilation rate is acquired, the deviation in the baseline carbon dioxide concentration corresponding to the deviation between the predicted occupancy information and the reference occupancy information and the deviation between the acquired ventilation rate and the reference ventilation rate may be identified, and the identified deviation may be used to correct the baseline carbon dioxide concentration, thereby predicting the carbon dioxide concentration in the air-conditioned space 3 for the prediction period. The correspondence relationship may also be obtained, for example, using regression analysis.

[0096] Furthermore, in the present embodiment, a case has been mainly described in which, when the maximum value of the carbon dioxide concentration in the prediction period exceeds a threshold value, the determination unit 25 determines, within a period in which the predicted temperature or predicted specific enthalpy of the outside air acquired by the acquisition unit 21 is within a predetermined range, the time before the time when the carbon dioxide concentration in the prediction period will be maximum and the time closest to the time when the carbon dioxide concentration will be maximum, as the time to introduce outside air, but this is not necessarily the case. The determination unit 25 may determine the time to introduce outside air and the amount of introduction of outside air by another method as long as it can determine the time and amount of introduction of outside air so that the maximum value of the carbon dioxide concentration in the prediction period is equal to or less than the threshold value and the heat load of the air-conditioned space 3 is lowered.

[0097] Furthermore, in this embodiment, information that changes over time, such as predicted temperature, predicted specific enthalpy, number of people information, ventilation rate, carbon dioxide concentration, etc., is information for each predetermined unit period (e.g., 1 hour, 15 minutes, 10 minutes, 5 minutes, 1 minute, etc.), and it is preferable that the predetermined unit period is common to all of the information. On the other hand, if the predetermined unit period is not common to multiple pieces of information, for example, the unit periods of the multiple pieces of information may be adjusted to a longer unit period by integrating the information of multiple consecutive unit periods by averaging, or the unit periods of the multiple pieces of information may be adjusted to a shorter unit period by dividing the information of multiple consecutive unit periods by interpolation, etc.

[0098] Furthermore, in the above embodiment, the case where the determination device 20 is included in the air conditioning system 1 has been described, but the determination device 20 does not have to be included in the air conditioning system 1. In this case, the determination device 20 may determine the timing and amount of outside air to be introduced and output the determination result to the control unit 30 of the air conditioner 10. As an example, the determination device 20 may be a server device in a server-client system. Then, the determination device 20 may determine the timing and amount of outside air to be introduced into the air-conditioned space 3 during the prediction period and transmit the determination result to the control unit 30 of the air conditioner 10. In this case, the output unit 26 may transmit the determination result to the control unit 30, for example.

[0099] Furthermore, in the present embodiment, the case where the air conditioner 10 also adjusts the temperature of the air supplied to the air-conditioned space 3 has been mainly described, but this is not necessarily the case. The air conditioner 10 is for introducing outside air into the air-conditioned space 3, and the temperature of the air supplied to the air-conditioned space 3 may be adjusted by another air conditioner separately. In this case, the air conditioner 10 does not need to be equipped with the coil 13.

[0100] Furthermore, in the above embodiments, each process or function may be realized by centralized processing by a single device or a single system, or may be realized by distributed processing by multiple devices or multiple systems.

[0101] Furthermore, in the above embodiments, the transfer of information between components may be performed, for example, by one component outputting information and the other component receiving information if the two components transferring the information are physically different, or by moving from a processing phase corresponding to one component to a processing phase corresponding to the other component if the two components transferring the information are physically the same.

[0102] Furthermore, in the above-described embodiments, information related to the processing performed by each component, such as information accepted, acquired, selected, generated, transmitted, or received by each component, and information such as thresholds, formulas, and addresses used in processing by each component, may be temporarily or long-term stored in a recording medium (not shown), even if not explicitly stated in the above description. Furthermore, the storage of information in the recording medium (not shown) may be performed by each component or a storage unit (not shown). Furthermore, the reading of information from the recording medium (not shown) may be performed by each component or a reading unit (not shown).

[0103] Furthermore, in the above-described embodiments, if the information used by each component, such as thresholds, addresses, and various setting values ​​used by each component in processing, may be changed by the user, the user may or may not be able to change the information as appropriate, even if not explicitly stated in the above description. If the information is changeable by the user, the change may be realized, for example, by a receiving unit (not shown) that receives a change instruction from the user and a changing unit (not shown) that changes the information in accordance with the change instruction. The change instruction may be received by the receiving unit (not shown), for example, from an input device, by receiving information transmitted via a communication line, or by receiving information read from a predetermined recording medium.

[0104] Furthermore, in the above embodiment, when two or more components included in the determination device 20 have a communication device, an input device, etc., the two or more components may have a single physical device or may have separate devices.

[0105] Furthermore, in the above-described embodiments, each component may be configured by dedicated hardware, or a component that can be realized by software may be realized by executing a program. For example, each component may be realized by a program execution unit such as a CPU reading and executing a software program recorded on a recording medium such as a hard disk or semiconductor memory. During execution, the program execution unit may execute the program while accessing a storage unit or recording medium. Note that the software that realizes the determination device 20 in the above-described embodiments is a program such as the following. In other words, this program may cause a computer to perform the following steps: acquiring a predicted temperature or predicted specific enthalpy of outside air for a specified prediction period; predicting number of people information regarding the number of people present in the air-conditioned space into which outside air will be introduced during the prediction period; predicting the carbon dioxide concentration in the air-conditioned space during the prediction period using the number of people information predicted in the number of people information predicting step; and determining the timing and amount of outside air to be introduced into the air-conditioned space using the predicted temperature or predicted specific enthalpy of outside air acquired in the step of acquiring the predicted temperature or predicted specific enthalpy of outside air and the carbon dioxide concentration predicted in the step of predicting the carbon dioxide concentration; and in the step of determining the timing and amount of outside air to be introduced, the program may determine the timing and amount of outside air to be introduced so that the maximum carbon dioxide concentration during the prediction period is below a threshold and the thermal load of the air-conditioned space is lowered.

[0106] In the above program, the acquisition step of acquiring information does not include processing that can only be performed by hardware, such as processing that can be performed by a modem or interface card in the acquisition step.

[0107] This program may be executed by being downloaded from a server or the like, or by being read from a predetermined recording medium (for example, an optical disk such as a CD-ROM, a magnetic disk, or a semiconductor memory). This program may also be used as a program constituting a program product.

[0108] Furthermore, the computer that executes this program may be a single computer or multiple computers, and may perform centralized processing or distributed processing.

[0109] 9 is a diagram showing the internal configuration of a computer system 900. In Fig. 9, the computer system 900 includes a computer 901, a keyboard 902, a mouse 903, and a monitor 904. The computer 901 also includes a CD-ROM drive 905, an MPU (Micro Processing Unit) 911, a ROM 912 for storing programs such as a boot-up program, a RAM 913 connected to the MPU 911 for temporarily storing instructions for application programs and providing temporary storage space, a hard disk 914 for storing application programs, system programs, and data, and a bus 915 for interconnecting the MPU 911, the ROM 912, and the like. The computer 901 may also include a network card (not shown) for providing connection to a LAN, WAN, or the like.

[0110] A program that causes the computer system 900 to execute the functions of the determination device 20 according to the above embodiment may be stored on a CD-ROM 921, inserted into the CD-ROM drive 905, and transferred to the hard disk 914. Alternatively, the program may be transmitted to the computer 901 via a network (not shown) and stored on the hard disk 914. The program is loaded into the RAM 913 when executed. The program may be loaded directly from the CD-ROM 921 or the network. The program may also be read into the computer system 900 via another recording medium (e.g., a DVD) instead of the CD-ROM 921.

[0111] The program does not necessarily include an operating system (OS) or a third-party program that causes the computer 901 to execute the functions of the decision device 20 according to the above embodiment. The program may include only a portion of instructions that call appropriate functions or modules in a controlled manner to achieve a desired result. How the computer system 900 operates is well known, and a detailed description thereof will be omitted.

[0112] Furthermore, the above-described embodiments are merely examples for specifically implementing the present invention, and are not intended to limit the technical scope of the present invention. The technical scope of the present invention is defined by the claims, not by the description of the embodiments, and is intended to include modifications within the literal scope of the claims and within the scope of equivalent meanings. [Explanation of symbols]

[0113] 1. Air conditioning system 3 Air-conditioned space 10 Air conditioner 20 Determination device 21 Acquisition Department 22 Number Prediction Department 23 Ventilation volume acquisition unit 24 Carbon dioxide concentration prediction section 25 Decision Section 26 Output section 27 Memory section 30 Control Unit

Claims

1. an acquisition unit that acquires a predicted temperature or a predicted specific enthalpy of outside air for a predetermined prediction period; a number-of-people prediction unit that predicts number-of-people information regarding the number of people present in the air-conditioned space that introduces outside air during the prediction period; a carbon dioxide concentration prediction unit that predicts a carbon dioxide concentration in the air-conditioned space during the prediction period using the number of people information predicted by the number of people prediction unit; and a determination unit that determines the timing and amount of introduction of outside air into the air-conditioned space using the predicted temperature or predicted specific enthalpy of the outside air acquired by the acquisition unit and the carbon dioxide concentration predicted by the carbon dioxide concentration prediction unit, The determination unit determines the timing and amount of outside air to be introduced so that the maximum value of carbon dioxide concentration during the prediction period is equal to or less than a threshold value and the heat load of the air-conditioned space is reduced.

2. The determination device according to claim 1 , wherein the carbon dioxide concentration prediction unit predicts the carbon dioxide concentration by correcting a baseline carbon dioxide concentration corresponding to past measurement results for the air-conditioned space using information about the number of people predicted by the number of people prediction unit.

3. The determination device according to claim 2 , wherein the carbon dioxide concentration prediction unit predicts the carbon dioxide concentration by correcting a baseline carbon dioxide concentration having the same attributes as the prediction period using the number of people information predicted by the number of people prediction unit.

4. a ventilation volume acquisition unit that acquires a ventilation volume of the air-conditioned space during the prediction period; The determination device according to claim 1 , wherein the carbon dioxide concentration predicting unit predicts the carbon dioxide concentration using the number of people information predicted by the number of people predicting unit and the ventilation volume acquired by the ventilation volume acquiring unit.

5. 5. The determination device according to claim 4, wherein the carbon dioxide concentration prediction unit predicts the carbon dioxide concentration by correcting a baseline carbon dioxide concentration corresponding to past measurement results for the air-conditioned space using information about the number of people predicted by the number of people prediction unit and the ventilation volume acquired by the ventilation volume acquisition unit.

6. 2. The determination device according to claim 1, wherein, when the maximum value of the carbon dioxide concentration in the prediction period exceeds a threshold value, the determination unit determines, as the time to introduce outside air, a time that is closest to and before the time when the carbon dioxide concentration in the prediction period becomes maximum, within a period in which the predicted temperature or predicted specific enthalpy of the outside air acquired by the acquisition unit is within a predetermined range.

7. The determination device according to claim 1 , wherein the number of people information is a crowd density.

8. A determination device according to any one of claims 1 to 7; an air conditioning device that introduces outside air into the air-conditioned space; a control unit that controls the air conditioner so that outside air is introduced into the air-conditioned space in accordance with the introduction timing and amount of outside air determined by the determination unit.

9. A determination method that is processed using an acquisition unit, a number of people prediction unit, a carbon dioxide concentration prediction unit, and a determination unit, The acquisition unit acquires a predicted temperature or a predicted specific enthalpy of outside air for a predetermined prediction period; a step in which the number-of-people prediction unit predicts number-of-people information regarding the number of people present in the air-conditioned space that introduces outside air during the prediction period; a step in which the carbon dioxide concentration prediction unit predicts a carbon dioxide concentration in the air-conditioned space during the prediction period using the number of people information predicted in the step of predicting the number of people information; the determination unit determines a timing and amount of introduction of outside air into the air-conditioned space, using the predicted temperature or predicted specific enthalpy of the outside air acquired in the step of acquiring the predicted temperature or predicted specific enthalpy of the outside air and the carbon dioxide concentration predicted in the step of predicting the carbon dioxide concentration, In the step of determining the timing and amount of outside air to be introduced, the timing and amount of outside air to be introduced are determined so that the maximum carbon dioxide concentration during the prediction period is below a threshold value and the heat load of the air-conditioned space is lowered.

10. On the computer, obtaining a predicted temperature or specific enthalpy of the outside air for a predetermined prediction period; predicting number of people information regarding the number of people present in the air-conditioned space that introduces outside air during the prediction period; predicting a carbon dioxide concentration in the air-conditioned space during the prediction period using the number of people information predicted in the step of predicting the number of people information; determining a timing and amount of introduction of outside air into the air-conditioned space using the predicted temperature or predicted specific enthalpy of the outside air acquired in the step of acquiring the predicted temperature or predicted specific enthalpy of the outside air and the carbon dioxide concentration predicted in the step of predicting the carbon dioxide concentration; In the step of determining the timing and amount of outside air to be introduced, the program determines the timing and amount of outside air to be introduced so that the maximum carbon dioxide concentration during the prediction period is below a threshold value and the heat load of the air-conditioned space is reduced.

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