AIR-CONDITIONING SYSTEM, CONTROL METHOD, AND RECORDING MEDIUM

Description

TECHNICAL FIELD

The present disclosure relates to an air-conditioning system, a control method, and a program.

BACKGROUND ART

Air conditioners, including home air conditioners, automatically control temperature and humidity of an indoor environment to ensure comfort of occupants.

Patent Literature 1 discloses an air-conditioning control device including an acquisition unit, an operation mode determination unit, a temperature setting computation unit, and a setting transmission unit, wherein the operation mode determination unit performs at least one of processing of determining an operation mode of an air conditioner as cooling when an indoor temperature value and an indoor humidity value acquired by the acquisition unit are not included in temperature and humidity ranges corresponding to a comfort range and the indoor temperature value is higher than the range, or processing of determining the operation mode of the air conditioner as heating when the indoor temperature value and the indoor humidity value acquired by the acquisition unit are not included in the temperature and humidity ranges corresponding to the comfort ranges and the indoor temperature value is less than the range, and the setting transmission unit transmits the operation mode determined by the operation mode determiner.

CITATION LIST

Patent Literature

• Patent Literature 1: Unexamined Japanese Patent Application Publication No. 2016-17656

SUMMARY OF INVENTION

Technical Problem

According to the air-conditioning control device disclosed in Patent Literature 1, cooling or heating operation is performed when the indoor temperature value and the indoor humidity value are not included in the comfort range, thereby bringing the indoor temperature to the target value. However, a transient response, that is, an intermediate progress until the target value is reached, is not considered, which might cause an issue that occupants might feel a decrease in comfort in the process of bringing the indoor temperature to the target value.

The present disclosure is made in view of the above circumstances, and an objective of the present disclosure is to provide an air-conditioning system, a control method, and a program that can maintain comfort of a user by adjusting temperature and humidity in consideration of a transient response until the temperature or the humidity in an air-conditioned target area reaches a target value.

Solution to Problem

To achieve the above objective, an air-conditioning system according to the present disclosure includes a temperature adjuster to adjust temperature in an air-conditioned target area, a humidity adjuster to adjust humidity in the air-conditioned target area, a sensor to obtain environment information including the temperature or the humidity in the air-conditioned target area, and a controller. The controller includes an estimator to estimate time variations in the temperature and the humidity in the air-conditioned target area based on the environment information obtained by the sensor, target values of the temperature and the humidity, and a control schedule indicating time variations in outputs of the temperature adjuster and the humidity adjuster, a control determiner to optimally calculate the control schedule and determine an optimal control schedule based on the time variations in the temperature and the humidity estimated by the estimator and the target values, an adjuster controller to control the temperature adjuster and the humidity adjuster based on an optimal control schedule determined by the control determiner.

Advantageous Effects of Invention

The present disclosure can provide an air-conditioning system, a control method, and a program that can maintain comfort of a user by adjusting temperature and humidity in consideration of a transient response until the temperature or the humidity in an air-conditioned target area reaches a target value.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram illustrating an air-conditioning system according to Embodiment 1;

FIG. 2 is a block diagram illustrating a configuration of the air-conditioning system according to Embodiment 1;

FIG. 3 is a schematic diagram illustrating a heat load balance of a room in which the air-conditioning system according to Embodiment 1 is installed;

FIG. 4 is a diagram illustrating an example of indoor environment control performed by the air-conditioning system according to Embodiment 1;

FIG. 5 is a diagram illustrating temperature and absolute humidity in an air-conditioned target area of Embodiment 1;

FIG. 6 is a flowchart illustrating an air-conditioning process of Embodiment 1;

FIG. 7 is a block diagram illustrating a configuration of an air-conditioning system according to Embodiment 2;

FIG. 8 is a block diagram illustrating a configuration of an air-conditioning system according to Embodiment 3; and

FIG. 9 is a flowchart illustrating air-conditioning process of Embodiment 4.

DESCRIPTION OF EMBODIMENTS

Embodiment 1

An air-conditioning system 1 according to Embodiment 1 of the present disclosure is described with reference to FIGS. 1 to 6. In the drawings, the same reference signs denote the same or corresponding components. The air-conditioning system 1 according to Embodiment 1 is an air-conditioning system that adjusts temperature or humidity of air in an air-conditioned target area.

FIG. 1 is a schematic diagram illustrating the air-conditioning system 1 according to Embodiment 1. As illustrated in FIG. 1, the air-conditioning system 1 is installed in a room 100 and includes an air conditioner 10 that adjust temperature and humidity in an inside of the room 100, that is, the air-conditioned target area. The air conditioner 10 includes a temperature adjuster 11 that adjusts indoor temperature, a humidity adjuster 12 that adjusts indoor humidity, a controller 13 that controls the temperature adjuster 11 and the humidity adjuster 12, and an inputter 14 that receives user operation.

The air-conditioning system 1 includes an indoor temperature sensor 21 that detects indoor temperature, an indoor humidity sensor 22 that detects indoor humidity, a blown air temperature sensor 23 that detects temperature of air blown from the air conditioner, a blown air humidity sensor 24 that detects humidity of air blown from the air conditioner, an outdoor temperature sensor 25 that detects outdoor temperature, and an outdoor humidity sensor 26 that detects outdoor humidity.

The temperature adjuster 11 of the air conditioner 10 adjusts the indoor temperature by transporting heat to raise or lower the indoor temperature. The temperature adjuster 11 may be a heat pump cooling and heating device that performs a vapor compression refrigeration cycle. That is, the temperature adjuster 11 may include an unillustrated refrigerant circuit in which refrigerant circulates to perform a refrigeration cycle.

The humidity adjuster 12 adjusts the indoor humidity by absorbing or discharging moisture from the air to raise or lower the indoor humidity. The humidity adjuster 12 may include a solid moisture absorbent to adjust the indoor humidity. The indoor humidity may be adjusted by absorbing moisture from one of the indoor air and the outside air and discharging the moisture to the other.

The controller 13 controls the temperature adjuster 11 and the humidity adjuster 12 to bring the indoor temperature or the indoor humidity closer to the target temperature or the target humidity, respectively. The controller 13 can include, but is not limited to, a processor, including a central control device, and a storage device. The process by which the controller 13 controls the temperature adjuster 11 and the humidity adjuster 12 is described later.

The inputter 14 receives user operations to turn on/off the air-conditioning system 1, sets target values of temperature or humidity, indicate start and end of indoor environment control, and sends the operations to the controller 13. The inputter 14 is connected to the controller 13 by wired or wireless connection. The inputter 14 can be, but is not limited to, a remote controller or a smartphone or tablet with an app installed.

The indoor temperature sensor 21, the blown air temperature sensor 23, and the outdoor temperature sensor 25 are disposed inside the room, at an air outlet of the air conditioner 10, and outside the room, respectively, and are temperature sensors that measure surrounding temperature. The indoor temperature sensor 21, the blown air temperature sensor 23, and the outdoor temperature sensor 25 are connected to the controller 13.

The indoor humidity sensor 22, the blown air humidity sensor 24, and the outdoor humidity sensor 26 are disposed inside the room, at the air outlet of the air conditioner 10, and outside the room, respectively, and are humidity sensors that measure surrounding humidity. The indoor humidity sensor 22, the blown air humidity sensor 24, and the outdoor humidity sensor 26 are connected to the controller 13. The indoor temperature sensor 21, the indoor humidity sensor 22, the blown air temperature sensor 23, the blown air humidity sensor 24, the outdoor temperature sensor 25, and the outdoor humidity sensor 26 are collectively referred to as a sensor group.

The process by which the controller 13 controls the temperature adjuster 11 and the humidity adjuster 12 is described. The controller 13 creates an optimal control schedule representing output of the temperature adjuster 11 or the humidity adjuster 12 from the start of control to the end of control, and controls the temperature adjuster 11 or the humidity adjuster 12 based on the optimal control schedule to execute the indoor environment control.

FIG. 2 is a block diagram illustrating a configuration of the air-conditioning system 1. As illustrated in FIG. 2, the controller 13 is connected via a bus to the temperature adjuster 11, the humidity adjuster 12, the inputter 14, the indoor temperature sensor 21, the indoor humidity sensor 22, the blown air temperature sensor 23, the blown air humidity sensor 24, the outdoor temperature sensor 25, and the outdoor humidity sensor 26.

The controller 13 includes an estimator 31 that estimates a time variation in the indoor temperature and the indoor humidity, a control determiner 32 that determines the optimal control schedule, a storage 33 that stores model information 34, a model modifier 35 that modifiers the model information 34, and an adjuster controller 36 that controls the temperature adjuster 11 and the humidity adjuster 12 to adjust the temperature and the humidity.

The estimator 31 estimates the time variation in the indoor temperature and the indoor humidity in a case where the indoor environment control is performed based on the control schedule.

The estimator 31 obtains a value indicating the target value of the temperature or the humidity from the inputter 14 operated by a user, and sets the target value of the temperature or the humidity based on the obtained value.

The estimator 31 obtains environment information indicating the indoor and outdoor temperature or humidity from the indoor temperature sensor 21, the indoor humidity sensor 22, the outdoor temperature sensor 25, and the outdoor humidity sensor 26.

The estimator 31 creates the control schedule indicating the time variations in the outputs of the temperature adjuster 11 and the humidity adjuster 12 from the start of control and the end of control. The process by which the estimator 31 creates the control schedule is described below.

FIG. 3 is a schematic diagram illustrating a heat load balance of the room 100 in which the air-conditioning system 1 according to Embodiment 1 is installed. For explanation, the temperature adjuster 11 is assumed to be a room air conditioner that includes an air conditioner indoor unit 15 and an air conditioner outdoor unit 16 connected to each other by refrigerant piping 17 and perform heating operation. The humidity adjuster 12 is assumed to be a humidifier 18. That is, the air-conditioning system 1 includes the air conditioner indoor unit 15, which is a heater, and the humidifier 18 to perform heating and humidification operation.

In FIG. 3, Q is sensible heat emitted from the air conditioner indoor unit 15, that is, heater output. H is latent heat emitted from the humidifier 18, that is, humidifier output or humidification volume. q is outdoor air volume and can include ventilation or draft. C is heat capacity in the air-conditioned target area, R is thermal resistance between indoor air and outdoor air, T_in is indoor temperature, X_in is indoor absolute humidity, T_out is outdoor temperature, and X_out is outdoor absolute humidity. In reality, other heat balances occur, including solar radiant heat, heat loads due to an occupant 40, and heat loads due to lighting or other equipment, but for simplicity, these are not considered here.

The sensible heat load balance and latent heat load balance can be expressed by the following differential equations (1) and (2), respectively.

[ Equation ⁢ 1 ]  ρ ⁢ CpV ⁢ dT in dt = ( T out - T in ) R + ρ ⁢ Cpq ⁡ ( T out - T in ) + Q ( 1 ) [ Equation ⁢ 2 ]  ρ ⁢ L w ⁢ V ⁢ dX in dt = ρ ⁢ L w ⁢ q ⁡ ( X out - X in ) + H ( 2 )

Hem, L_w represents latent heat of evaporation of water.

The heat capacity C of the air-conditioned target area can be expressed by the following equation (3) using density ρ of air, specific heat Cp of air, and volume V of the air-conditioned target area.

C = ρ × Cp × V ( 3 )

The information indicated by Equations (1) to (3) is stored in the storage 33 as the model information 34.

The estimator 31 substitutes the indoor temperature, the indoor humidity, the outdoor temperature, and the outdoor humidity at the start of control, that is, the environment information at the start of control, obtained from the sensor group, into the equation included in the model information 34 obtained from the storage 33. In other words, the environment information at the start of control is input into the model information 34. The estimator 31 substitutes time-varying heating capacity Q(t) and humidification capacity H(t) into the equation included in the model information 34. In other words, the control schedule of heating and humidification is input in the model information 34. By approximating a numerical solution of the differential equation included in the model information 34 with discrete values, the estimator 31 estimates the time variation in the indoor temperature and the indoor humidity, that is, transient response, when the input control schedule is executed. In other words, the estimator 31 outputs information indicating the transient response of the indoor temperature and the indoor humidity from the environment information at the start of control and the model information 34 in which the control schedule is input.

The control determiner 32 determines the optimal control schedule, which is one of the control schedules, based on the target values of the indoor temperature and the indoor humidity, and time variations in the indoor temperature and the indoor humidity output by the estimator 31. The method by which the control determiner 32 determines the optimal control schedule can include, but is not limited to, optimal calculation.

The optimal control schedule is described. FIG. 4 is a drawing illustrating an example of the indoor environment control performed by the air-conditioning system 1. The configuration of the air-conditioning system 1 is assumed to be similar to the example of FIG. 3. In FIG. 4, the horizontal axis indicates time, and the vertical axis indicates the output (W) from the air conditioner indoor unit 15 that is the heater, that is, heating capacity, the output (mLh) from the humidifier 18, that is humidification volume, the time transition (° C.) of the indoor temperature, and the time transition (%) of the indoor humidity.

T_set° C. is a target value of the indoor temperature set via the inputter 14 by a user, RH_set % is a target value of the indoor humidity, and (T_set−α)° C. is indoor temperature at 0 min, which is the start of control. The indoor humidity at the start of control is assumed to be near the target value. In this case, the output of the air conditioner indoor unit 15 and the humidifier 18 that quickly brings the indoor temperature to the target value while maintaining the indoor humidity near the target value is the optimal control schedule.

The controller 13 determines the optimal control schedule to obtain the indoor temperature and humidity responses that are comfortable for the occupant 40 before 0 min, which is the time of the start of control. In FIG. 4, the solid line 41 indicates the output of the heater based on the optimal control schedule determined by the control determiner 32 of the controller 13, the dotted line 43 indicates the output of the humidifier, the solid line 44 indicates the time transition of the indoor temperature, and the dotted line 46 indicates the time transition of the indoor humidity.

According to the optimal control schedule determined by the control determiner 32, as shown in the solid line 41, the heater starts and the indoor air is heated by the heater from 0 min to 20 min, and the indoor temperature thereby rises from (T_set−α)° C. to T_set° C. as shown in the solid line 44. As the indoor temperature approaches the target value, the heating capacity decreases as indicated by the solid line 41, and after 20 min, the heater output is balanced with the sensible heat load and the indoor temperature stabilizes.

According to the optimal control schedule, the heater increases its output to bring the indoor temperature closer to the target value, as shown by the solid line 41, and the humidifier also increases its output, as shown by the dotted line 43. This allows the indoor temperature to approach the target value, as shown by the solid line 44, while the indoor humidity remains at the target value, as shown by the dotted line 46.

As an example of conventional control that reduces the comfort of the occupant 40, a case of separate control of the indoor temperature and the indoor humidity is described. In FIG. 4, the solid line 41 indicates the output of the heater, the solid line 42 indicates the output of the humidifier, the solid line 44 indicates the time transition of the indoor temperature, and the solid line 45 indicates the time transition of the indoor humidity. For comparison, the output of the heater and the time transition of the indoor temperature are the same as those according to the optimal control schedule determined by the control determiner 32.

According to the conventional example control, the indoor temperature approaches the target value as shown by the solid line 44, while the indoor humidity decreases to (RH_set−β)% as shown by the solid line 45. After the indoor temperature reaches the target value at 20 min, the humidifier increases its output to bring the indoor humidity closer to the target value as shown by the solid line 42, and the indoor humidity approaches the target value as shown by the solid line 45. That is, according to the conventional example control, the indoor temperature approaches the target value, while the indoor humidity is away from the target value.

The indoor environment when the indoor environment control is performed in accordance with the optimal control schedule is described. FIG. 5 is a diagram illustrating temperature and absolute humidity in the air-conditioned target area. The point 47 in FIG. 5 shows the temperature and the humidity of the air-conditioned target area at the start of control, the point 48 shows the target values of the temperature and the humidity of the air-conditioned target area, and the dotted line 51 shows the time transition of the temperature and the humidity when the indoor environment control is performed in accordance with the optimal control schedule.

As shown by the dotted line 51 in FIG. 5, the sensible heat change due to the control of the heater and the latent heat change and humidity change due to the control of the humidifier occur simultaneously, and from the point 47 to the point 48, the lines indicating the indoor temperature and the indoor humidity follow the equal relative humidity line. In other words, one of the optimal control schedules is a control schedule that varies the indoor temperature and the indoor humidity along the equal relative humidity line. The optimal control schedule is not limited thereto.

The indoor environment when the indoor environment control is performed in accordance with the conventional example control is described. The solid lines 49 and 50 in FIG. 5 show the time transitions of the temperature and the humidity when the indoor environment control is performed in accordance with the conventional example control.

As shown by the solid line 49 in FIG. 5, the sensible heat change due to the control of the heater appears from the start of control. Assuming that there is no outdoor air volume including ventilation, the absolute humidity is constant, while the saturated water vapor content increases as the indoor temperature rises, resulting in a relative decrease in the amount of water vapor contained in the air per unit volume. Thus, when the indoor temperature reaches T_set° C., the indoor humidity, which is the relative humidity, decreases to (RH_set−β)%. To bring the indoor humidity to the target value, the relative humidity needs to increase by β %, and the latent heat change due to the control of the humidifier appears as shown by the solid line 50.

When the indoor environment control is performed in accordance with the conventional example control, a temporary drop in humidity occurs before the indoor environment reaches the target value from the initial state, leading to discomfort, including dry throat or dry skin, for the occupant 40.

The storage 33 stores information relating to the heat capacity of the air-conditioned target area, that is, density ρ of air, specific heat Cp of air, and volume V of the air-conditioned target area. The storage 33 stores information indicated by Equations (1) to (3) as the model information 34.

The adjuster controller 36 controls the temperature adjuster 11 and the humidity adjuster 12 based on the optimal control schedule created by the control determiner 32 to adjust the temperature and the humidity, that is, to perform the indoor environment control.

The model modifier 35 modifiers the model information 34 stored in the storage 33 at each modification interval Δt using time-series data of the indoor temperature and the indoor humidity, that is, response data of the indoor temperature and the indoor humidity, obtained by the adjuster controller 36 performing the indoor environment control based on the optimal control schedule, and updates the model information 34 to the latest one.

The model modifier 35 obtains the response data including time-series data T_in(t) of the indoor temperature, time-series data X_in(t) of the indoor humidity, time-series data T_out(t) of the outdoor temperature, and time-series data X_out(t) of the outdoor absolute humidity, obtained by executing the indoor environment control.

The model modifier 35 estimates, from data output and obtained from the blown air temperature sensor 23 and the blown air humidity sensor 24, the time-series data Q(t) of sensible heat load and the time-series data H(t) of latent heat load output from the air conditioner 10 by the controller 13 executing the indoor environment control, respectively.

The model modifier (35) modifies the model information 34 using each of the obtained time-series data T_in(t), X_in(t), T_out(t), X_out(t), Q(t), and H(t). Specifically, the model information 34 is updated by calculating a model parameter for which the indoor temperature and humidity responses calculated from Equations (1) and (2) match the obtained actual responses, and replacing the parameter included in the model information 34 with the calculated model parameter. The model parameter to be calculated can include, but are not limited to, the thermal resistance R between the indoor air and the outdoor air and/or the outdoor air volume q.

The smaller modification interval Δt of the model information 34 enables more precise following of changes in the indoor heat load environment. For example, when the control cycle of the temperature adjuster 11 or the humidity adjuster 12 is the same as the modification interval Δt of the model information, the control schedule corresponding to the indoor heat load environment can be determined each time, thereby making it easier to obtain accurate indoor temperature and humidity responses. On the other hand, the smaller modification interval Δt increases the computation load. That is, Δt is determined by the trade-off relationship between the control performance and the computation load. Δt may be changed by a user inputting via the inputter 14.

When the estimator 31 estimates the transient response of the indoor temperature and humidity using the model information 34, a difference between the estimated value and the actual responses may occur. This may be due in part to changes in the indoor heat load environment, including changes in the number of occupants 40, the opening and closing of windows by occupants 40 for ventilation purposes, and the generation of heat load due to cooking, but the causes of the change in the indoor heat load environment is not limited thereto. There can also be causes other than changes in the indoor heat load environment, including errors in the heater or output.

If a discrepancy occurs between the estimated value and the actual response, even if the optimal control schedule determined by the control determiner 32 is executed, the indoor temperature and humidity responses may not be as expected, leading to reduced comfort for the occupant 40. The difference between the estimated value and the actual responses can be eliminated by the model modifier 35 modifying the model information 34.

FIG. 6 is a flowchart illustrating the air-conditioning process executed by the air-conditioning system 1 according to Embodiment 1. The air-conditioning process executed by the air-conditioning system 1 is described with reference to the flowchart of FIG. 6.

Upon start of the air-conditioning process, the estimator 31 of the controller 13 of the air-conditioning system 1 obtains values indicating the target values of the temperature and the humidity from the inputter 14 operated by a user, and sets the target values of the temperature and the humidity based on the obtained values (step S101).

Upon the setting of the target values, the estimator 31 obtains, from a group of sensors, the environment information including the indoor temperature, the indoor humidity, the outdoor temperature, and the outdoor humidity at the start of control (step S102).

Upon the obtaining of the environment information, the estimator 31 inputs to the model information 34 the obtained environment information and the control schedule of the heating and humidification, and estimates the time variations in the indoor temperature and the indoor humidity (step S103).

Upon the estimation of the time variations in the indoor temperature and the indoor humidity by the estimator 31, the control determiner 32 determines the optimal control schedule of the heating and the humidification based on the target values of the indoor temperature and the indoor humidity and the time variations in the indoor temperature and the indoor humidity output by the estimator 31 (step S104).

Upon the determination of the optimal control schedule by the control determiner 32, the adjuster controller 36 controls the temperature adjuster 11 and the humidity adjuster 12 based on the optimal control schedule to execute environment control (step S105).

Upon the execution of the environment control, the model modifier 35 determines whether the modification interval Δt has elapsed (step S106).

When determination is made that the modification interval Δt has not elapsed (No in step S106), the processing returns to step S105 and continues the environment control.

When determination is made that the modification interval Δt has elapsed (Yes in step S106), the model modifier 35 obtains, from the group of sensors, time-series data of the indoor temperature, the indoor humidity, the outdoor temperature, and the outdoor humidity, and the time-series data of the sensible heat load and the latent heat load, and modifies the model information 34 based on the obtained data (step S107).

Upon the modification of the model information 34 by the model modifier 35, the controller 13 determines whether an instruction to stop control of the indoor temperature and the indoor humidity is input via the inputter 14 by a user (step S108). When determination is made that the instruction is not input (No in step S108), the processing returns to steps S102.

When determination is made that the instruction is input (Yes in step S108), the air-conditioning process ends.

By providing the above configuration and executing the air-conditioning process, the air-conditioning system 1 according to Embodiment 1 can maintain user comfort by adjusting the temperature and the humidity in consideration of the transient response until the temperature or the humidity in the air-conditioned target area reaches the target value.

The characteristics of the air-conditioned target area can be altered by frequently changing factors, including the number of occupants 40 or the frequency of ventilation. By modifying the model information 34 at each modification interval Δt, the air-conditioning system 1 according to Embodiment 1 can create the optimal control schedule that follows changes in the characteristics of the air-conditioned target area, and adjust the temperature and the humidity of the air-conditioned target area.

If the sensible or latent heat load output from the air conditioner 10 is estimated only from voltage or frequency, the error between the actual sensible or latent heat load in a control target area and the estimated value may become large in a case where the piping between the indoor unit and the outdoor unit is long. By estimating the sensible and latent heat loads from the data output by the blown air temperature sensor 23 and the blown air humidity sensor 24, respectively, the air-conditioning system 1 according to Embodiment 1 can reduce the error between the actual and estimated values in the control target area and perform accurate control.

Embodiment 2

An air-conditioning system 1 according to Embodiment 2 of the present disclosure is described with reference to FIG. 7. The air-conditioning system 1 according to Embodiment 2 includes a server 2 having the function of the controller 13.

FIG. 7 is a block diagram illustrating a configuration of the air-conditioning system 1 according to Embodiment 2. As illustrated in FIG. 7, the air-conditioning system 1 according to Embodiment 2 includes the server 2. The server 2 has the function of the controller 13. That is, the server 2 includes the estimator 31, the control determiner 32, the storage 33, the model modifier 35, and the adjuster controller 36.

The server 2 is installed in the same building as where the air-conditioning system 1 is installed. The server 2 may be a server for controlling a plurality of air-conditioning systems including the air-conditioning system 1 or a cloud server connected via the Internet to the plurality of air-conditioning systems including the air-conditioning system 1.

In a case where the server 2 is a cloud server connected via the Internet to the air-conditioning system 1, the environment information detected by the group of sensors and the information input by a user through the inputter 14 are transmitted via the Internet to the server 2. The server 2 determines the optimal control schedule based on the transmitted information, similarly to the controller 13 in Embodiment 1. The determined optimal control schedule is transmitted via the Internet from the server 2 to the temperature adjuster 11 or the humidity adjuster 12, and the temperature adjuster 11 or the humidity adjuster 12 is controlled by the optimal control schedule.

With the above configuration and by executing the air-conditioning process, the air-conditioning system 1 according to Embodiment 2 has the same effects as the air-conditioning system 1 according to Embodiment 1.

The air-conditioning system 1 according to Embodiment 2 having the server 2 can obtain the data or the model information 34 of the plurality of air-conditioning systems and use lots of data, which can generate an optimal control schedule that leads to more user comfort and adjust temperature and humidity.

Embodiment 3

An air-conditioning system 1 according to Embodiment 3 of the present disclosure is described with reference to FIG. 8. The air-conditioning system 1 according to Embodiment 3 includes a server 2 including artificial intelligence.

FIG. 8 is a block diagram illustrating a configuration of the air-conditioning system 1 according to Embodiment 3. As illustrated in FIG. 8, the air-conditioning system 1 according to Embodiment 3 includes the server 2, and the server 2 includes a learning device 61 that generates a learned model, and an inference device 62 that generates an optimal control schedule using the learned model.

The learning device 61 generates a learned model to infer the optimal control schedule from environment information and target values based on the environment information provided as input and obtained from the group of sensors and the target values obtained from the inputter 14, and time-series data of the sensible heat load and the latent heat load provided as output.

The inference device 62 receives as input the environment information obtained from the group of sensors and the target values obtained from the inputter 14, and thereby infers the optimal control schedule using the learned model generated by the learning device 61.

With the above configuration and by executing the air-conditioning process, the air-conditioning system 1 according to Embodiment 3 has the same effects as the air-conditioning system 1 according to Embodiment 1.

By generating the learned model and inferring the optimal control schedule, the air-conditioning system 1 according to Embodiment 3 can also use the learned model created by another air-conditioning system, which can enhance user comfort even with shorter working time.

Embodiment 4

An air-conditioning system 1 according to Embodiment 4 of the present disclosure is described with reference to FIG. 9. The configuration of the air-conditioning system 1 according to Embodiment 4 is similar to the air-conditioning system 1 according to Embodiment 1. The air-conditioning system 1 according to Embodiment 4 determines the modification interval Δt of the model information 34 after modification of the model information 34.

After modifying the model information 34, a model modifier 35 of Embodiment 4 calculates a time average value of a difference between the estimated time variations in the indoor temperature and the indoor humidity and the time variation in the indoor temperature and indoor humidity obtained from the environment information, and stores the time average value in the storage 33. The model modifier 35 compares the time average value of the difference calculated after modification of the previous model information 34 stored in the storage 33 with the time average value of the difference calculated after modification of the current model information 34 at each modification of the model information 34, and determines a modification interval Δt based on the result of comparison until modification of the next model information 34. The model modifier may have at least one of an upper or lower limit for the modification interval Δt of the model information 34. The model modifier 35 may compare the time average value of the difference calculated after modification of the current model information 34 with the time average value of the difference calculated after modification of the model information 34 that is information prior to the previous one.

When the time average value of the difference calculated after modification of the current model information 34 is greater than the time average value of the difference calculated after modification of the previous model information 34, estimation accuracy of the time variations in the indoor temperature and the indoor humidity by the estimator 31 may be lower. In this case, the model modifier 35 may reduce the modification interval Δt. The model modifier 35 can increase the accuracy of the model information 34 by reducing the modification interval Δt.

When the time average value of the difference calculated after modification of the current model information 34 is less than the time average value calculated after modification of the previous model information 34, the estimator 31 can be considered to have estimated the time variations in the indoor temperature and the indoor humidity with sufficient accuracy. In this case, the model modifier 35 may increase the modification interval Δt. The model modifier 35 can reduce the computation load by increasing the modification interval Δt. The accuracy of the model information 34 can be increased.

FIG. 9 is a flowchart illustrating the air-conditioning process executed by the air-conditioning system 1 according to Embodiment 4. The air-conditioning process executed by the air-conditioning system 1 is described with reference to the flowchart of FIG. 9. Steps S101 to S108 in the flowchart of FIG. 9 are similar to steps S101 to S108 in the flowchart of FIG. 6 in Embodiment 1.

In step S107, when the model modifier 35 modifies the model information 34, the model modifier 35 calculates the time average value of the difference between the estimated time variations in the indoor temperature and the indoor humidity and the time variations in the indoor temperature and the indoor humidity obtained from the environment information. The model modifier 35 then compares the time average value of the difference between the time average value of the difference calculated after modification of the previous model information 34 with the time average value of the difference calculated after modification of the current model information 34. The model modifier 35 then determines the modification interval Δt based on the result of comparison until modification of the next model information 34 (step S109), and the processing proceeds to step S108.

With the above configuration and by executing the air-conditioning process, the air-conditioning system 1 according to Embodiment 4 has the same effects as the air-conditioning system 1 according to Embodiment 1.

The air-conditioning system 1 according to Embodiment 4 determines the modification interval Δt of the model information 34 based on the time average value of the difference between the estimated time variations in the indoor temperature and the indoor humidity and the time variations in the indoor temperature and the indoor humidity obtained from the environment information, which can thereby enhance the accuracy of the model information 34 or the computation load.

An example of a case in which the modification interval Δt of the model information 34 is to be smaller is when the heat load of the room 100 in which the air-conditioning system 1 is installed varies during operation of the air conditioner 10. This can happen when ventilation is started and ended and when the number of people in the room 100 increases or decreases.

Another example in which the modification interval Δt of the model information 34 is to be smaller is when humidity return occurs during cooling operation of the air conditioner 10. When the air conditioner 10 is stopped during cooling operation or when the compressor frequency is reduced, a phenomenon called humidity return, in which humidity increases, may occur. Moisture condensing on the heat exchanger of the air conditioner indoor unit 15 during cooling operation of the air conditioner 10 falls through the heat exchanger to the inside bottom of the air conditioner indoor unit 15 and is discharged outside the room through a drain hose. Since discharging of moisture takes time, when the temperature of the indoor heat exchanger rises, including when the air conditioner 10 is stopped during cooling operation or when the compressor frequency is lowered, the saturated water vapor content increases and the moisture attached to the heat exchanger evaporates, causing humidity return in which highly humid air is blown out into the room.

Occurrence of the humidity return, in which the humidity in the dehumidified room 100 rises again during cooling operation of the air conditioner 10, may lead to discomfort for the occupant 40 and deterioration of energy-saving performance. Thus, when the humidity return occurs during cooling operation of the air conditioner 10, increasing the dehumidification capacity of the humidity adjuster 12 is desirable.

To estimate the time variations in the indoor temperature and the indoor humidity in consideration of the humidity return, estimating the amount of moisture retained by the air conditioner indoor unit 15 is needed. The amount of moisture retained in the air conditioner indoor unit 15 is an amount obtained by subtracting the amount of moisture discharged outdoors through the drain hose from the sum of the amount of moisture adhered at the start of operation and the amount of moisture condensed on the heat exchanger. The amount of moisture condensed on the heat exchanger can be calculated from the environment information, but it is difficult to calculate the amount of moisture adhered at the start of operation and the amount of moisture discharged outdoors from the environment information.

By determining the modification interval Δt of the model information 34 based on the time average value of the difference between the estimated time variations in the indoor temperature and the indoor humidity and the time variations in the indoor temperature and the indoor humidity obtained from the environment information, the air-conditioning system 1 according to Embodiment 4 can improve the accuracy of the model information 34 by reducing the modification interval Δt of the model information 34 even without the time variations in the indoor temperature and the indoor humidity in consideration of the humidity return by estimating the amount of moisture retained in the air conditioner indoor unit 15.

Modified Example

Embodiments of the present disclosure are not limited to the embodiment descried above, and modifications can be made. For example, the air-conditioning system 1 includes the humidity adjuster 12, but this is a mere example. Instead of the humidity adjuster 12, the air-conditioning system 1 may include at least one of a humidifier, including an ultrasonic humidifier and an evaporative humidifier, or a dehumidifier, including an adsorption dehumidifier.

The controller 13 includes the model modifier 35, but this is a mere example. The controller 13 not having the model modifier 35 may be provided and the controller 13 does not have to perform modification of the model information 34.

The storage 33 stores information relating to the heat capacity of the air-conditioned target area, that is, density ρ of air, specific heat Cp of air, and volume V of the air-conditioned target area, but this is a mere example. Multiple candidates for the volume V of the air-conditioned target area corresponding to the capacity range of the air conditioner 10 may be stored, allowing correction or selection through input by a user via the inputter 14.

When estimating the response of the indoor humidity, relative humidity may be estimated as the unit instead of absolute humidity. The transient response RH(t) of the indoor relative humidity can be obtained from the indoor temperature T_in(T) and the indoor absolute humidity X_in(t). Specifically, the transient response RH(t) can be derived using a psychrometric chart or an approximation formula that models the information of the psychrometric chart, shown in Equation (4). The storage 33 stores the psychrometric chart or Equation (4) as the model information 34.

RH_in(t)=f(T_in(t),X_in(t))  (4)

The model information shown in Equations (1) to (4) may be stored in the storage 33 as a model discretized by the control cycle. The control cycle is, for example, 1 second, but this is a mere example.

In the above description, a user is present in a room, which is the air-conditioned target area, and operates the inputter 14, but this is a mere example. The user operating the inputter 14 may be not necessarily present in the room, and an occupant 40 other than the user operating the inputter 14 may be present in the room.

In Embodiment 1, the air-conditioning system 1 is described as performing heating and humidification operation using a heater and a humidifier, but this is a mere example, and similar effects can be achieved in any of the heating and humidification operation, cooling and humidification operation, cooling and dehumidification operation, and any combination thereof.

The air-conditioning system 1 according to Embodiment 2 includes the server 2 having the function of the controller 13, but this is a mere example. The air-conditioning system 1 may include the controller 13 as well as the server 2.

The air-conditioning system 1 according to Embodiment 3 includes the server 2 including artificial intelligence, but this is a mere example. The air-conditioning system 1 may include a controller 13 including artificial intelligence. That is, the controller 13 may include the learning device 61 and the inference device 62. The air-conditioning system 1 may include the controller 13 not including artificial intelligence and the server 2 including artificial intelligence, or may include the controller 13 including artificial intelligence and the server 2 not including artificial intelligence.

In Embodiment 3, the server 2 may learn based on training data transmitted from a plurality of air-conditioning systems operating in different air-conditioned target areas from the room where the air-conditioning system 1 is installed. The server 2 may infer the optimal control schedule using a learned model transmitted from another air-conditioning system.

Hereinafter, various aspects of the present disclosure are recited as appendices.

APPENDIX 1

An air-conditioning system, comprising:

• • a temperature adjuster to adjust temperature in an air-conditioned target area;
  • a humidity adjuster to adjust humidity in the air-conditioned target area;
  • a sensor to obtain environment information including the temperature or the humidity in the air-conditioned target area; and
  • a controller, wherein
  • the controller includes
    • an estimator to estimate time variations in the temperature and the humidity in the air-conditioned target area based on the environment information obtained by the sensor, target values of the temperature and the humidity, and a control schedule indicating time variations in outputs of the temperature adjuster and the humidity adjuster,
    • a control determiner to optimally calculate the control schedule and determine an optimal control schedule based on the time variations in the temperature and the humidity estimated by the estimator and the target values, and
    • an adjuster controller to control the temperature adjuster and the humidity adjuster based on the optimal control schedule determined by the control determiner.

APPENDIX 2

The air-conditioning system according to appendix 1, wherein

• • the estimator estimates the time variations in the temperature and the humidity in the air-conditioned target area by inputting the environment information, the target values, and the control schedule to model information indicating a relationship between the environment information, the target values, and the control schedule, and
  • the controller further includes
    • a storage to store the model information, and
    • a model modifier to modify the model information stored in the storage.

APPENDIX 3

The air-conditioning system according to appendix 2, wherein the model modifier modifies the model information stored in the storage at each modification interval using time-series data of the environment information obtained by the sensor.

APPENDIX 4

The air-conditioning system according to any one of appendices 1 to 3, wherein the environment information includes at least one of temperature of air blown from the temperature adjuster, humidity of air blown from the humidity adjuster, temperature outside the air-conditioned target area, or humidity outside the air-conditioned target area.

APPENDIX 5

The air-conditioning system according to any one of appendices 1 to 4, further comprising:

• • a server including the controller, wherein
  • the server is connected to the temperature adjuster, the humidity adjuster, and the sensor.

APPENDIX 6

The air-conditioning system according to any one of appendices 1 to 5, wherein the controller generates a learned model from the environment information, the target values, and the control schedule, and generate the optimal control schedule using the learned model.

APPENDIX 7

The air-conditioning system according to appendix 6, wherein

• • the controller further includes
    • a learning device to obtain the environment information and the target values as input, obtain the control schedule as output, and generate the learned model to infer the optimal control schedule from the environment information and the target values, and
    • an inference device to infer the optimal control schedule based on the learned model generated by the learning device and the environment information and the target values.

APPENDIX 8

The air-conditioning system according to appendix 3, wherein

• • after modifying the model information, the model modifier calculates a time average value between the time variation in the temperature or the humidity in the air-conditioned target area estimated by the estimator and the time variation in the temperature or the humidity in the air-conditioned target area obtained from the environment information obtained by the sensor, and stores the calculated time average value in the storage, and
  • the model modifier compares the time average value calculated after modifying the immediately preceding model information with the time average value calculated after modifying the model information prior to modifying the immediately preceding model information, and determining a modification interval of the model information based on a result of the comparison.

APPENDIX 9

A control method, comprising:

• • obtaining environment information including temperature or humidity in an air-conditioned target area;
  • estimating time variations in the temperature and the humidity in the air-conditioned target area based on the environment information, the target values of the temperature and the humidity, and a control schedule indicating a time variation in output of a temperature adjuster that adjusts the temperature in the air-conditioned target area and a time variation in output of a humidity adjuster that adjusts the humidity in the air-conditioned target area,
  • optimally calculating the control schedule and determining an optimal control schedule based on the estimated time variations in the temperature and the humidity and the target values, and
  • controlling the temperature adjuster and the humidity adjuster based on the optimal control schedule.

APPENDIX 10

A program causing a computer to:

• • obtain environment information including temperature or humidity in an air-conditioned target area;
  • estimate time variations in the temperature and the humidity in the air-conditioned target area based on the environment information, the target values of the temperature and the humidity, and a control schedule indicating a time variation in output of a temperature adjuster that adjusts the temperature in the air-conditioned target area and a time variation in output of a humidity adjuster that adjusts the humidity in the air-conditioned target area,
  • optimally calculate the control schedule and determine an optimal control schedule based on the estimate time variation in the temperature and the humidity and the target value, and
  • control the temperature adjuster and the humidity adjuster based on the optimal control schedule.

The foregoing describes some example embodiments for explanatory purposes. Although the foregoing discussion has presented specific embodiments, persons skilled in the art will recognize that changes may be made in form and detail without departing from the broader spirit and scope of the invention. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. This detailed description, therefore, is not to be taken in a limiting sense, and the scope of the invention is defined only by the included claims, along with the full range of equivalents to which such claims are entitled.

This application claims the benefit of Japanese Patent Application No. 2022-182120, filed on Nov. 14, 2022, the entire disclosure of which is incorporated by reference herein.

INDUSTRIAL APPLICABILITY

The present disclosure can be preferably used as an air-conditioning system, a control method, and a program.

REFERENCE SIGNS LIST

• • 1 Air-conditioning system
  • 10 Air conditioner
  • 11 Temperature adjuster
  • 12 Humidity adjuster
  • 13 Controller
  • 14 Inputter
  • 15 Air conditioner indoor unit
  • 16 Air conditioner outdoor unit
  • 17 Refrigerant connection piping
  • 18 Humidifier
  • 21 Indoor temperature sensor
  • 22 Indoor humidity sensor
  • 23 Blown air temperature sensor
  • 24 Blown air humidity sensor
  • 25 Outdoor temperature sensor
  • 26 Outdoor humidity sensor
  • 31 Estimator
  • 32 Control determiner
  • 33 Storage
  • 34 Model information
  • 35 Model modifier
  • 36 Adjuster controller
  • 40 Occupant
  • 41 Output of heater
  • 42, 43 Output of humidifier
  • 44 Time transition of indoor temperature
  • 45, 46 Time transition of indoor humidity
  • 47 Temperature and humidity at start of control
  • 48 Target values of temperature and humidity
  • 49-51 Time transitions of temperature and humidity
  • 61 Learning device
  • 62 Inference device
  • 100 Room
  • C Heat capacity
  • H Humidifier output
  • Q Heater output
  • q Outdoor air volume
  • R Thermal resistance
  • T_in Indoor temperature
  • T_out Outdoor temperature
  • X_in Indoor absolute humidity
  • X_out Outdoor absolute humidity