AIR-CONDITIONING SYSTEM, AIR-CONDITIONING CONTROLLER, AIR CONDITIONER, AND AIR-CONDITIONING CONTROL METHOD

Abstract

 An air conditioning system includes an air conditioner (11) and an air conditioning controller (50, 55), in which the air conditioning controller has, as a control mode, a first mode in which the air conditioner performs a preheating operation or a precooling operation at or after a first time (te) set in advance and at or before a second time (ts) at which the target space is used next, the first mode is a control mode of operating the air conditioner and stopping the air conditioner when the temperature of the target space increases to a preheating temperature (T_H) higher than a target temperature (T_M) of the target space at the second time (ts) or when the temperature of the target space decreases to a precooling temperature (T_L) lower than the target temperature (T_M), the preheating temperature (T_H) is set such that the temperature of the target space becomes the target temperature (T_M) or higher than the target temperature (T_M) at a point of the second time (ts), and the precooling temperature (T_L) is set such that the temperature of the target space becomes the target temperature (T_M) or lower than the target temperature (T_M) at the point of the second time (ts).

Description

TECHNICAL FIELD

[0001] The present disclosure relates to an air conditioning system, an air conditioning controller, an air conditioner, and an air conditioning control method.

BACKGROUND ART

[0002] PATENT LITERATURE 1 discloses an air conditioning controller connected to an air conditioning apparatus via a network. The air conditioning controller predicts a temperature of a room in future after turning off the air conditioning apparatus, and causes the air conditioning apparatus to perform a preheating operation on the basis of the prediction in advance so that an indoor temperature reaches a target temperature at a time when the room is used next. In addition, a technique disclosed in Patent Literature 1 reduces a temperature difference between a set temperature and the indoor temperature to save energy by gradually increasing the set temperature of the air conditioning apparatus during the preheating operation.

CITATION LIST

[PATENT LITERATURE]

[0003] PATENT LITERATURE 1: Japanese Laid-Open Patent Publication No. 2017-67427

SUMMARY OF THE INVENTION

[TECHNICAL PROBLEM]

[0004] In the technique disclosed in PATENT LITERATURE 1, the air conditioning apparatus is operated so that the indoor temperature is increased several tens of minutes to several hours before the time when the room is used next, and the indoor temperature reaches the target temperature exactly at the time when the room is used. However, in a case where the room is an office, if the air conditioning apparatus is turned off at night when work is finished and the indoor temperature is to reach the target temperature at the time when work is started the next morning, the air conditioning apparatus needs to be operated in a time zone when the outside temperature is low early morning, which causes poor energy efficiency.

[0005] An object of the present disclosure is to provide an air conditioning system, an air conditioning controller, an air conditioner, and an air conditioning control method that enable operation under better conditions in terms of energy efficiency and the like.

[SOLUTION TO PROBLEM]

[0006] 

(1) An air conditioning system of the present disclosure includes an air conditioner that adjusts a temperature of a target space, and an air conditioning controller that controls the air conditioner, in which the air conditioning controller has, as a control mode, a first mode in which the air conditioner performs a preheating operation or a precooling operation at or after a first time set in advance and at or before a second time at which the target space is used next, the first mode is control of operating the air conditioner and stopping the air conditioner when the temperature of the target space increases to a preheating temperature higher than a target temperature of the target space at the second time or when the temperature of the target space decreases to a precooling temperature lower than the target temperature, the preheating temperature is set such that the temperature of the target space becomes the target temperature or higher than the target temperature at a point of the second time due to a decrease of the temperature of the target space after the air conditioner stops in the first mode, and the precooling temperature is set such that the temperature of the target space becomes the target temperature or lower than the target temperature at the point of the second time due to an increase of the temperature of the target space after the air conditioner stops in the first mode.
In the air conditioning system having the above configuration, by controlling the air conditioner in the first mode, the temperature of the target space is increased or decreased from a temperature closer to the target temperature than immediately before the second time, and thereafter, the temperature of the target space can be brought close to the target temperature by a natural temperature decrease or temperature rise. Therefore, an energy-efficient operation can be performed.

(2) Preferably, the air conditioning controller has a second mode as a control mode together with the first mode, in a case where the first mode is a control mode in which the air conditioner performs the preheating operation, the second mode is a control mode in which the air conditioner is operated from a temperature lower than the target temperature at the second time to increase the temperature of the target space to the target temperature, in a case where the first mode is a control mode in which the air conditioner performs the precooling operation, the second mode is a control mode in which the air conditioner is operated from a temperature higher than the target temperature at the second time to decrease the temperature of the target space to the target temperature, and the air conditioning controller selects and executes either the first mode or the second mode on the basis of a predetermined determination criterion. Such a configuration enables the air conditioner to be operated in a more appropriate control mode in accordance with a predetermined determination criterion.

(3) The second mode is preferably a control mode of causing the temperature of the target space to reach the target temperature at the second time.

(4) The second mode may be a control mode in which the air conditioner is operated from the second time to cause the temperature of the target space to reach the target temperature.

(5) The air conditioning controller preferably executes a control mode of the first mode or the second mode with a lower energy consumption.

(6) The air conditioning controller may execute a control mode of the first mode or the second mode with a lower electricity charge.

(7) The air conditioning controller preferably executes the first mode or the second mode on the basis of an energy consumption obtained in consideration of heat insulation performance in the target space.
Since the heat insulation performance of the target space affects the energy consumption, a more appropriate control mode can be executed by considering the heat insulation performance of the target space in obtaining the energy consumption.

(8) The air conditioning controller preferably executes the first mode or the second mode on the basis of an energy consumption obtained in consideration of a predicted value of an outside temperature at or after the first time.
Since the outside temperature affects the energy consumption, a more appropriate control mode can be executed by considering the predicted value of the outside temperature in obtaining the energy consumption.

(9) The air conditioning controller preferably executes the first mode or the second mode on the basis of an energy consumption obtained in consideration of a predicted value of a difference between a temperature of the target space and the outside temperature at or after the first time.
Since the difference between the temperature of the target space and the outside temperature affects the energy consumption, a more appropriate control mode can be executed by considering the predicted value of the difference between the temperature of the target space and the outside temperature in obtaining the energy consumption.

(10) The air conditioning controller executes the first mode and the second mode on the basis of an energy consumption obtained in consideration of necessity of a defrost operation in accordance with a predicted value of the outside temperature.
Since the energy consumption is increased by performing the defrost operation, a more appropriate control mode can be executed by considering necessity of the defrost operation in obtaining the energy consumption.

(11) The first time is preferably a time when the target space is not in use.

(12) The first time is preferably a time when the air conditioner is stopped in a schedule operation.

(13) The first time is preferably a time at which no person appears in the target space.

(14) The present disclosure is an air conditioning controller that controls an air conditioner that adjusts a temperature of a target space, in which the air conditioning controller has, as a control mode, a first mode in which the air conditioner performs a preheating operation or a precooling operation at or after a first time set in advance and at or before a second time at which the target space is used next, the first mode is control of operating the air conditioner and stopping the air conditioner when the temperature of the target space increases to a preheating temperature higher than a target temperature of the target space at the second time or when the temperature of the target space decreases to a precooling temperature lower than the target temperature, the preheating temperature is set such that the temperature of the target space becomes the target temperature or higher than the target temperature at a point of the second time due to a decrease of the temperature of the target space after the air conditioner stops in the first mode, and the precooling temperature is set such that the temperature of the target space becomes the target temperature or lower than the target temperature at the point of the second time due to an increase of the temperature of the target space after the air conditioner stops in the first mode.
In the air conditioning controller having the above configuration, by controlling the air conditioner in the first mode, the temperature of the target space is increased or decreased from a temperature closer to the target temperature than immediately before the second time, and thereafter, the temperature of the target space can be brought close to the target temperature by a natural temperature decrease or temperature rise. Therefore, an energy-efficient operation can be performed.

(15) The present disclosure is an air conditioner that adjusts a temperature of a target space, the air conditioner including a control unit that has, as a control mode, a first mode in which the air conditioner performs a preheating operation or a precooling operation at or after a first time set in advance and at or before a second time at which the target space is used next, in which the first mode is control of operating the air conditioner and stopping the air conditioner when the temperature of the target space increases to a preheating temperature higher than a target temperature of the target space at the second time or when the temperature of the target space decreases to a precooling temperature lower than the target temperature, the preheating temperature is set such that the temperature of the target space becomes the target temperature or higher than the target temperature at a point of the second time due to a decrease of the temperature of the target space after the air conditioner stops in the first mode, and the precooling temperature is set such that the temperature of the target space becomes the target temperature or lower than the target temperature at the point of the second time due to an increase of the temperature of the target space after the air conditioner stops in the first mode.
In the air conditioner having the above configuration, by controlling the air conditioner in the first mode by the control unit, the temperature of the target space is increased or decreased from a temperature closer to the target temperature than immediately before the second time, and thereafter, the temperature of the target space can be brought close to the target temperature by a natural temperature decrease or temperature rise. Therefore, an energy-efficient operation can be performed.

(16) The present disclosure is an air conditioning control method of controlling an air conditioner that adjusts a temperature of a target space, the air conditioning control method including operating the air conditioner in a first step at or after a first time set in advance and at or before a second time at which the target space is used next, and stopping the air conditioner in a second step when the temperature of the target space increases to a preheating temperature higher than a target temperature of the target space at the second time or decreases to a precooling temperature lower than the target temperature, in which the preheating temperature is set such that the temperature of the target space becomes the target temperature or higher than the target temperature at a point of the second time due to a decrease of the temperature of the target space after the air conditioner stops in the second step, and the precooling temperature is set such that the temperature of the target space becomes the target temperature or lower than the target temperature at the point of the second time by an increase of the temperature of the target space after the air conditioner stops in the second step.

[0007] In the air conditioning control method having the above configuration, by controlling the air conditioner in the first mode, the temperature of the target space is increased or decreased from a temperature closer to the target temperature than immediately before the second time to a temperature higher or lower than the target temperature, and thereafter, the temperature of the target space can be brought close to the target temperature by a natural temperature decrease or temperature rise. Therefore, an energy-efficient operation can be performed.

BRIEF DESCRIPTION OF DRAWINGS

[0008] 

FIG. 1 is a schematic configuration diagram of an air conditioning system according to Embodiment 1 of the present disclosure.

FIG. 2 is a block diagram of the air conditioning system.

FIG. 3 is a graph illustrating changes in an outdoor temperature and an indoor temperature after the air conditioner is stopped at a predetermined time.

FIG. 4 is a flowchart of processing of determining a control mode in efficiency priority control.

FIG. 5 is a graph illustrating changes in the outdoor temperature and the indoor temperature after the air conditioner is stopped at a predetermined time in an air conditioning system according to Embodiment 2.

FIG. 6 is a schematic configuration diagram of an air conditioning system according to another embodiment.

DETAILED DESCRIPTION

[0009] Embodiments of an air conditioning management system will be described in detail below with reference to the accompanying drawings.

Embodiment 1

[0010] FIG. 1 is a schematic configuration diagram of an air conditioning system according to Embodiment 1 of the present disclosure. FIG. 2 is a block diagram of the air conditioning system.

[0011] The air conditioning system includes an air conditioner 11 and a centralized management apparatus (air conditioning controller) 50. The air conditioner 11 adjusts a temperature of air in a room, which is a target space for air conditioning, to a predetermined target temperature. The air conditioner 11 according to the present embodiment performs a heating operation for increasing at least an indoor temperature.

[0012] The air conditioner 11 includes an indoor unit 21 and an outdoor unit 22. The air conditioner 11 according to the present embodiment is a multi-type air conditioner in which a plurality of indoor units 21 is connected in parallel to the outdoor unit 22, and is applied to a building having multiple target spaces for air conditioning, for example. In an example illustrated in FIG. 1, two indoor units 21 are connected to one outdoor unit 22. However, the number of the outdoor units 22 and the number of the indoor units 21 are not limited.

[0013] The air conditioner 11 includes a refrigerant circuit 23. The refrigerant circuit 23 circulates a refrigerant between the indoor units 21 and the outdoor unit 22. The refrigerant circuit 23 includes a compressor 30, a four-way switching valve 32, an outdoor heat exchanger (heat source heat exchanger) 31, an outdoor expansion valve 34, a liquid shutoff valve 36, indoor expansion valves 24, indoor heat exchangers (utilization heat exchangers) 25, a gas shutoff valve 37, and refrigerant pipes 40L and 40G connecting these elements.

[0014] Each of the indoor units 21 includes an indoor expansion valve 24 and an indoor heat exchanger 25 included in the refrigerant circuit 23. The indoor expansion valve 24 includes an electric expansion valve capable of adjusting a refrigerant flow rate. The indoor heat exchanger 25 is a cross fin tube type or microchannel type heat exchanger, and is used for exchanging heat with indoor air.

[0015] Each of the indoor units 21 further includes an indoor fan 26 and an indoor temperature sensor 27. The indoor fan 26 is configured to take indoor air into the indoor unit 21, cause the indoor heat exchanger 25 to exchange heat with the taken-in air, and then blow the air into the room. The indoor fan 26 includes a motor of which number of revolutions is adjustable by inverter control. The indoor temperature sensor 27 detects the indoor temperature.

[0016] The outdoor unit 22 includes the compressor 30, the four-way switching valve 32, the outdoor heat exchanger 31, the outdoor expansion valve 34, the liquid shutoff valve 36, and the gas shutoff valve 37 that are included in the refrigerant circuit 23.

[0017] The compressor 30 sucks a low-pressure gas refrigerant and discharges a high-pressure gas refrigerant. The compressor 30 includes a motor of which number of revolutions is adjustable by inverter control. The compressor 30 is of a variable capacity type (ability variable type) having capacity (ability) that is changeable by inverter control of the motor. Alternatively, the compressor 30 may be of a constant capacity type. A plurality of compressors 30 may be provided. In this case, compressors 30 of a variable capacity type and compressors 30 of a constant capacity type may coexist.

[0018] The four-way switching valve 32 reverses a refrigerant flow in the refrigerant pipe, and switches and supplies the refrigerant discharged from the compressor 30 to either the outdoor heat exchanger 31 or the indoor heat exchanger 25. As a result, the air conditioner 11 can switch between a cooling operation and a heating operation. The air conditioner 11 according to the present embodiment only needs to be able to perform at least the heating operation, and the four-way switching valve 32 can be omitted when only the heating operation is performed.

[0019] The outdoor heat exchanger 31 is, for example, a cross fin tube type or microchannel type heat exchanger, and is used for exchanging heat with a refrigerant by using air as a heat source.

[0020] The outdoor expansion valve 34 includes an electric expansion valve capable of adjusting the refrigerant flow rate and the like.

[0021] The liquid shutoff valve 36 is a manual on-off valve. The gas shutoff valve 37 is also a manual on-off valve. The liquid shutoff valve 36 and the gas shutoff valve 37 are closed to block a refrigerant flow in the refrigerant pipes 40L and 40G, and are opened to allow a refrigerant flow in the refrigerant pipes 40L and 40G.

[0022]  The outdoor unit 22 further includes an outdoor fan 33, a suction pressure sensor 35, a discharge pressure sensor 41, a suction temperature sensor 38, a discharge temperature sensor 42, and the like. The outdoor fan 33 includes a motor of which number of revolutions is adjustable by inverter control. The outdoor fan 33 is configured to take outdoor air into the outdoor unit 22, cause the outdoor heat exchanger 31 to exchange heat with the taken-in air, and then blow the air out of the outdoor unit 22.

[0023] The suction pressure sensor 35 detects a pressure of the refrigerant sucked into the compressor 30. The discharge pressure sensor 41 detects a pressure of the refrigerant discharged from the compressor 30. The suction temperature sensor 38 detects a temperature of the refrigerant sucked into the compressor 30. The discharge temperature sensor 42 detects a temperature of a refrigerant discharged from the compressor 30. An evaporation pressure, a condensation pressure, a degree of superheating, and the like of the outdoor heat exchanger 31 and the indoor heat exchanger 25 are obtained by using detection values of the refrigerant pressure sensors 35 and 41 and the refrigerant temperature sensors 38 and 42, and the number of revolutions of the compressor 30, an opening degree of the outdoor expansion valve 34, and the like are controlled so as to adjust these values.

[0024] During the cooling operation by the air conditioner 11 having the above configuration, the four-way switching valve 32 is held in a state indicated by solid lines in FIG. 1. A high-temperature and high-pressure gaseous refrigerant discharged from the compressor 30 flows into the outdoor heat exchanger 31 through the four-way switching valve 32, and exchanges heat with outdoor air by operation of the outdoor fan 33 to be condensed and liquefied. The liquefied refrigerant flows into each of the indoor units 21 through the outdoor expansion valve 34 in a fully open state. In each of the indoor units 21, the refrigerant is decompressed to a predetermined low pressure by the indoor expansion valve 24, and the refrigerant exchanges heat with indoor air in the indoor heat exchanger 25 to evaporate. The indoor air cooled by the evaporation of the refrigerant is blown into the room by the indoor fan 26 to cool the room. The refrigerant evaporated in the indoor heat exchanger 25 returns to the outdoor unit 22 through the gas refrigerant pipe 40G, passes through the four-way switching valve 32, and is sucked into the compressor 30. The air conditioner 11 operates in a similar manner to the cooling operation when performing a defrost operation of removing frost adhering to the outdoor heat exchanger 31.

[0025] During the heating operation performed by the air conditioner 11, the four-way switching valve 32 is held in a state indicated by broken lines in FIG. 1. A high-temperature and high-pressure gaseous refrigerant discharged from the compressor 30 passes through the four-way switching valve 32, and flows into the indoor heat exchanger 25 of each of the indoor units 21. In the indoor heat exchanger 25, the refrigerant exchanges heat with the indoor air to be condensed and liquefied. The indoor air heated by the condensation of the refrigerant is blown into the room by the indoor fan 26 to heat the room. The refrigerant liquefied in the indoor heat exchanger 25 returns to the outdoor unit 22 through the liquid refrigerant pipe 40L, is decompressed to a predetermined low pressure by the outdoor expansion valve 34, and further exchanges heat with outdoor air in the outdoor heat exchanger 31 to evaporate. The refrigerant evaporated and vaporized by the outdoor heat exchanger 31 is sucked into the compressor 30 through the four-way switching valve 32.

[0026] The indoor unit 21 further includes an indoor control unit 29. The indoor control unit 29 includes a microcomputer and the like including a central processing unit (CPU) and a memory. Detection values of the sensors provided in the indoor unit 21 are input to the indoor control unit 29. The indoor control unit 29 controls operations of the indoor expansion valve 24 and the indoor fan 26 on the basis of the detection values of the sensors and the like.

[0027] The outdoor unit 22 further includes an outdoor control unit 39. The outdoor control unit 39 includes a microcomputer and the like including a CPU and a memory. Detection values of the sensors provided in the outdoor unit 22 are input to the outdoor control unit 39. The outdoor control unit 39 controls operations of the outdoor expansion valve 34, the compressor 30, the outdoor fan 33, and the like on the basis of detection values of the sensors and the like.

[0028] The indoor control unit 29 and the outdoor control unit 39 are communicably connected to each other via a transmission line. The indoor control unit 29 and the outdoor control unit 39 are connected to the centralized management apparatus 50 via a transmission line. The centralized management apparatus 50 includes a control unit 50a such as a microcomputer including a calculation unit such as a CPU and a storage such as a ROM and a RAM. The centralized management apparatus 50 is installed, for example, in a central management room of a building. The centralized management apparatus 50 manages the outdoor unit 22 and the indoor unit 21. Specifically, the centralized management apparatus 50 monitors an operation status of the outdoor unit 22 and the indoor unit 21, sets an air conditioning temperature, controls operation and stop, and the like by the control unit 50a.

[0029] The centralized management apparatus 50 according to the present embodiment executes a schedule operation as control of operation and stop of the air conditioner 11. This schedule operation is an operation of starting the operation of the air conditioner 11 at a predetermined time (second time) and ending the operation of the air conditioner 11 at a predetermined time (first time). The first time and the second time are set as follows, for example. In a case where the air conditioning system is applied to an office building, the first time is set to a time between 18:00 and 22:00, for example, in accordance with a closing time of a company that occupies the office building, and the second time is set to a time between 6:00 and 10:00, for example, in accordance with an opening time of the company. Each of the first time and the second time is stored in the storage provided in the centralized management apparatus 50.

[0030] The centralized management apparatus 50 according to the present embodiment executes "efficiency priority control" to cause the indoor temperature at the second time to efficiently reach a target temperature T_M. Hereinafter, this efficiency execution control will be described in detail.

[Specific example of efficiency priority control]

[0031] During a normal heating operation performed by the air conditioner 11, the indoor control unit 29 obtains a required ability necessary for causing the indoor temperature to reach the target temperature (set temperature) on the basis of the temperature detected by the indoor temperature sensor 27, the indoor target temperature, and the like, and controls the opening degree of the indoor expansion valve 24, the number of revolutions of the indoor fan 26, and the like. On the other hand, the outdoor control unit 39 controls the compressor 30 so as to satisfy the required ability obtained by the indoor control unit 29. In this case, since it is prioritized to cause the indoor temperature to quickly reach the target temperature, the compressor 30 is operated at a large number of revolutions. Therefore, energy efficiency deteriorates, and energy consumption increases. In addition, a strong wind blown from the indoor fan 26 could increase noise or make a person hit by the strong wind uncomfortable. Therefore, an air volume of the indoor fan 26 is suppressed, and heating efficiency is lowered. As described above, the normal heating operation is not necessarily operated in an optimum state in terms of energy consumption and heating efficiency.

[0032] On the other hand, when there is no person in the room, for example, between the closing time (first time) and the starting time (second time) of a company, it is possible to efficiently operate the compressor 30 at a number of revolutions with a small energy consumption or operate the indoor fan 26 at a number of revolutions with a high heating efficiency, and it is possible to efficiently heat the room while reducing the energy consumption. Therefore, the centralized management apparatus 50 according to the present embodiment has a control mode for performing a preheating operation between the first time and the second time as one form of the "efficiency priority control".

<Details of control mode>

[0033] FIG. 3 is a graph illustrating changes in an outdoor temperature T_out and an indoor temperature T_in after the air conditioner 11 is stopped at a predetermined time. A graph indicated by a thick solid line in FIG. 3 represents the indoor temperature T_in. In FIG. 3, the air conditioner 11 is stopped at a first time te. A graph indicated by a thin solid line in FIG. 3 represents the outdoor temperature (outside temperature) T_out.

[0034] The outdoor temperature T_out gradually decreases at night (for example, from slightly before the first time te to the second time ts in FIG. 3), and then turns to increase in the morning. On the other hand, the indoor temperature T_in is maintained at the predetermined target temperature T_M by the air conditioner 11 until the first time te (for example, 20:00), and at or after the first time te, indoor heat is released to the outside of the room from outer walls, windows, and the like of the building due to the stop of the air conditioner 11, and gradually decreases. In the present embodiment, the centralized management apparatus 50 executes the efficiency priority control to adjust the indoor temperature T_in at a point of the second time ts to the target temperature T_M. At this time, the compressor 30 is operated at a number of revolutions with a high energy efficiency, for example, a number of revolutions of about 50% to 60% of a maximum number of revolutions, and the indoor fan 26 is operated at a maximum number of revolutions. The indoor fans 26 of all the indoor units 21 are operated.

[0035] The centralized management apparatus 50 according to the present embodiment has two control modes of a "first mode" and a "second mode" as the efficiency priority control, and selects and executes one of the control modes on the basis of a predetermined condition.

[0036] In FIG. 3, graphs indicated by (A) and (B) represent the indoor temperature T_in when control in the first mode is performed. The centralized management apparatus 50 stops the normal heating operation by the air conditioner 11 at the first time te by the schedule operation, and then starts the preheating operation by the air conditioner 11 before the second time ts. The control of the preheating operation in the first mode is control of operating the air conditioner 11 from the first time te to the second time ts, and stopping the air conditioner 11 when the indoor temperature increases to a predetermined temperature (preheating temperature) T_H higher than the indoor target temperature T_M at the second time ts. The preheating temperature T_H is set such that the indoor temperature reaches the target temperature T_M at the point of the second time ts by a decrease of the indoor temperature after the air conditioner 11 is stopped.

[0037] In the graph of (B), as a representative, ta, tb, T_L, and T_H are assigned to a preheating start time, a preheating end time, the indoor temperature at a time of starting the preheating, and the indoor temperature at a time of ending the preheating, respectively.

[0038] Immediately after the air conditioner 11 performs the heating operation until the first time te, the outdoor temperature T_out is higher than the second time ts. Therefore, there is a possibility that the air conditioner 11 can perform the heating operation with higher energy efficiency immediately after the first time te than immediately before the second time ts. In a case where heat insulation performance of the building is high, the indoor temperature is less likely to decrease. It is therefore not necessary to set the preheating temperature T_H so high, and the energy consumption is more likely to be suppressed.

[0039] In FIG. 3, a graph indicated by (C) represents the indoor temperature T_in in a case where control in the second mode is performed. The control of the preheating operation in the second mode is control to start the operation of the air conditioner 11 at or after the first time te and increase the indoor temperature to the target temperature T_M at the point of the second time ts. Therefore, unlike the preheating operation in the first mode, the preheating operation in the second mode does not increase the indoor temperature until the temperature exceeds the target temperature T_M.

(Selection condition of first mode and second mode)

[0040] The centralized management apparatus 50 selects and executes the first mode and the second mode on the basis of any of the following conditions.

(Condition 1) The energy consumption is lower.

(Condition 2) An electricity charge is lower.

[0041] The energy consumption by the air conditioner 11 can be obtained as follows.

[0042] As illustrated in FIG. 3, in a case where the preheating operation is performed by the air conditioner 11, energy consumption (electric power) P (J (= Ws)) can be expressed by the following equation (1).
[Math. 1]

[0043] In equation (1), COP_ave is an average value of coefficient of performance (COP) which is energy consumption efficiency (coefficient of performance) from the preheating start time ta to the preheating end time tb. Qa (J) is an amount of heat necessary to raise the indoor temperature from T_L to T_H, and can be expressed by the following equation (2).
[Math. 2]

[0044] Note that C (J/K) is a heat capacity of air or a building in the target space.

[0045] In equation (1), Qe (J) is a heat loss amount of the building from the time ta at which the preheating operation is started to the second time ts, and can be expressed by the following equation (3).
[Math. 3]

[0046] Note that η (W/K (= (J/s)/K)) is a heat loss coefficient of the building, and ΔT (K (or °C)) is a difference between the indoor temperature T_in and the outdoor temperature T_out.

[0047] In equation (3), the outdoor temperature T_out is a predicted value estimated at a point of the first time te. For example, as the outdoor temperature T_out, an average value or the like during the past several days is adopted. The outdoor temperature T_out may be obtained by machine learning using various factors related to the past outdoor temperature and outdoor temperature as inputs. The outdoor temperature T_out may be forecast information provided from a business operator such as a meteorological observatory. In either case, outdoor temperature information is stored in the storage of the centralized management apparatus 50 and used for calculation of the electric power and the like. The indoor temperature T_in is also a predicted value assumed at the point of the first time te. The indoor temperature T_in is estimated from the value of the outdoor temperature T_out in consideration of factors such as a structure, heat insulation performance, and floor area of the building, and is stored in the storage of the centralized management apparatus 50.

[0048] The centralized management apparatus 50 according to the present embodiment calculates values of P at a plurality of points between the first time te and the second time ts. Then, as illustrated in FIG. 3(b), a relationship between the preheating operation start time and the energy consumption (electric power) P is obtained. In a case where Condition 1 is adopted, the centralized management apparatus 50 selects the control mode with the lowest energy consumption and a start time of the control mode. In the example illustrated in FIG. 3, the energy consumption is the smallest in (B) of the first mode. Therefore, in a case where Condition 1 is adopted, the centralized management apparatus 50 starts the control in the first mode at the time ta.

[0049] On the other hand, in a case where Condition 2 is adopted, the centralized management apparatus 50 further multiplies the energy consumption (electric power) P by a charge per unit electric power (unit price) to obtain the electricity charge. The centralized management apparatus 50 selects the control mode with the lowest electricity charge and the start time of the control mode. Accordingly, it is possible to execute efficiency suppression control in which the electricity charge is suppressed. Since charge per unit electric power may be reduced depending on a time zone such as late at night, in a case where Condition 2 is adopted, the preheating operation advantageous in terms of not only a magnitude of the electric power P but also cost can be executed.

[0050] The heat insulation performance of the building to which the air conditioning system is applied has a great influence on a change in the indoor temperature T_in. For example, when the heat insulation performance of the building is high, a decrease in the indoor temperature becomes moderate even after the operation of the air conditioner 11 is stopped, and the indoor temperature can be increased in a short time. Therefore, in the present embodiment, by including the heat loss amount Qe in equation (1), the energy consumption can be obtained in consideration of a heat loss of the building from the preheating operation start time ta to the second time ts.

[0051] The COP indicating the energy consumption efficiency (coefficient of performance) of the air conditioner 11 is obtained from a heating ability (heating heat amount) and power consumption, and changes in accordance with the outdoor temperature T_out. The COP, which varies depending on device characteristics, can be obtained from the power consumption and the heating ability with reference to ISO 16358-2. On the other hand, in a case where the heating operation is performed by the air conditioner 11, when the outdoor temperature T_out is in a predetermined temperature range, for example, from 5.5°C to -7.0°C, the defrost operation of reversing the refrigerant flow in the refrigerant circuit is periodically performed, and frost adhering to the outdoor unit 22 is removed. During the defrost operation, the room is not heated, and electric power is consumed to melt frost, and thus the COP decreases. Therefore, when the preheating operation is performed in the temperature range in which the defrost operation occurs, the energy consumption increases. In the present embodiment, a value in consideration of the defrost operation is also adopted as COP_ave (see equation (1)) used for obtaining the energy consumption, and thus the preheating operation can be performed at a more appropriate timing.

(Processing of determining mode selection)

[0052] FIG. 4 is a flowchart of processing of determining a control mode in the efficiency priority control. In order to perform the efficiency priority control, the centralized management apparatus 50 determines whether the time has reached the first time te as illustrated in step S1 in FIG. 4. When determining that the time has reached the first time te, the centralized management apparatus 50 calculates an energy consumption (Condition 1) or an electricity charge (Condition 2) in a case where the efficiency priority control is performed at a plurality of points between the first time te and the second time ts (step S2).

[0053] The centralized management apparatus 50 determines which of the first mode or the second mode is advantageous in terms of energy consumption or electricity charge (step S3), and selects and executes a more advantageous control mode (steps S4 and S5). As described above, the air conditioner 11 performs appropriate preheating operation, and the indoor temperature can reach the target temperature T_M at the point of the second time ts.

Embodiment 2

[0054] The centralized management apparatus 50 according to Embodiment 2 has a control mode for performing a "precooling operation" between the first time and the second time as one form of "efficiency priority control". The air conditioner 11 according to the present embodiment performs the cooling operation for decreasing at least the indoor temperature.

<Details of control mode>

[0055] FIG. 5 is a graph illustrating changes in the outdoor temperature T_out and the indoor temperature T_in after the air conditioner 11 is stopped at a predetermined time in an air conditioning system according to Embodiment 2. A graph indicated by a thick solid line in FIG. 5 represents the indoor temperature T_in. In FIG. 5, the air conditioner 11 is stopped at the first time te. A graph indicated by a thin solid line in FIG. 5 represents the outdoor temperature (outside temperature) T_out.

[0056] In summer and the like, the outdoor temperature T_out gradually increases, for example, from early morning to daytime (for example, from slightly before the first time te to the second time ts in FIG. 5). On the other hand, the indoor temperature T_in is maintained at the predetermined target temperature T_M by the air conditioner 11 until the first time (for example, 6:00 am) te, and at or after the first time te, outdoor heat enters the room from outer walls, windows, and the like of the building due to the stop of the air conditioner 11, and gradually increases. In the present embodiment, the centralized management apparatus 50 executes the efficiency priority control to adjust the indoor temperature T_in at the point of the second time (for example, 12:00 pm) ts to the target temperature T_M. At this time, the compressor 30 is operated at a number of revolutions with a high energy efficiency, for example, a number of revolutions of about 50% to 60% of a maximum number of revolutions, and the indoor fan 26 is operated at a maximum number of revolutions. The indoor fans 26 of all the indoor units 21 are operated.

[0057] The centralized management apparatus 50 according to the present embodiment has two control modes of a "first mode" and a "second mode" as the efficiency priority control, and selects and executes one of the control modes on the basis of a predetermined condition.

[0058] In FIG. 5, graphs indicated by (A) and (B) represent the indoor temperature T_in when control in the first mode is performed. The centralized management apparatus 50 stops the normal cooling operation by the air conditioner 11 at the first time te by the schedule operation, and then starts the precooling operation by the air conditioner 11 before the second time ts. The control of the precooling operation in the first mode is control of operating the air conditioner 11 from the first time te to the second time ts, and stopping the air conditioner 11 when the indoor temperature decreases to a predetermined temperature (precooling temperature) T_L lower than the indoor target temperature T_M at the second time ts. The precooling temperature T_L is set such that the indoor temperature reaches the target temperature T_M at the point of the second time ts by an increase of the indoor temperature after the air conditioner 11 is stopped.

[0059] In the graph of (B), as a representative, ta, tb, T_H, and T_L are assigned to a precooling start time, a precooling end time, the indoor temperature at a time of starting the precooling, and the indoor temperature at a time of ending the precooling, respectively.

[0060] Immediately after the air conditioner 11 performs the cooling operation until the first time te, the indoor temperature T_in is closer to the target temperature T_M than immediately before the second time ts. Therefore, there is a possibility that the air conditioner 11 can perform the cooling operation with higher energy efficiency immediately after the first time te than immediately before the second time ts. However, immediately after the air conditioner 11 performs the cooling operation until the first time te, the outdoor temperature T_out is lower than the second time ts. Therefore, there is a possibility that the air conditioner 11 can perform the cooling operation with higher energy efficiency immediately after the first time te than immediately before the second time ts. In a case where heat insulation performance of the building is high, the indoor temperature is less likely to increase. It is therefore not necessary to set the precooling temperature T_L so low, and the energy consumption is more likely to be suppressed.

[0061] In FIG. 5, a graph indicated by (C) represents the indoor temperature T_in in a case where control in the second mode is performed. The control of the precooling operation in the second mode is control of starting the operation of the air conditioner 11 at or after the first time te and decreasing the indoor temperature to the target temperature T_M at the point of the second time ts. Therefore, unlike the precooling operation in the first mode, the precooling operation in the second mode does not decrease the indoor temperature until the temperature becomes lower than the target temperature T_M.

[0062] As in the case of Embodiment 1, the centralized management apparatus 50 according to the present embodiment selects and executes either the first mode or the second mode on condition that the energy consumption is lower or the electricity charge is lower. The energy consumption and the electricity charge by the air conditioner 11 can be calculated by replacing the calculation method in Embodiment 1 with the cooling operation (precooling operation). The centralized management apparatus 50 according to the present embodiment can perform processing of determining selection of a control mode in accordance with a procedure illustrated in the flowchart of FIG. 4.

Another Embodiment

(Second mode)

[0063] The second mode in the efficiency priority control described above is control of increasing or decreasing the indoor temperature to the target temperature T_M at the point of the second time ts. However, the second mode may be control of starting the operation at the second time ts. In this case, since the preheating operation and the precooling operation are performed only in the first mode, the efficiency priority control by the centralized management apparatus 50 is selected between the preheating operation or the precooling operation in the first mode and the normal operation in the second mode, and an operation with lower energy consumption or lower electricity charge is selected.

(First time)

[0064] The first time te described above is a time when the air conditioner 11 stops due to the schedule operation. However, any of the following times may be adopted as the first time te.

(a) Time at which no person appears in the target space.

(b) Time at which the target space is not in use any more.

[0065] In a case where the efficiency priority control is performed at the time of (a) or (b), the temperature of the target space is not required to reach the target temperature T_M quickly, and there is no need to consider a possibility of making a person uncomfortable. It is therefore possible to perform an operation with low energy consumption and high heating efficiency or high cooling efficiency.

[0066] In a case where (a) or (b) is adopted as the first time te, for example, the following means can be adopted in order to determine whether the time has reached the first time te.

(I) Detection of a person in the target space.

(II) Detection of illumination of the target space being turned off.

(III) Detection of the target space or the building being locked.

[0067]  The detection of (I) can be performed by installing a human sensor in the target space. Alternatively, a camera is installed in the target space, and presence or absence of a person can be determined by processing a captured image.

[0068] The detection of (II) can be performed by, for example, detecting, by a sensor, that illumination of the target space is turned off and receiving a detection signal of the sensor by the centralized management apparatus 50.

[0069] The detection of (III) can be performed by, for example, detecting, by a sensor, that the target space or the building is locked and receiving a detection signal of the sensor by the centralized management apparatus 50.

(Preheating temperature and precooling temperature)

[0070] In Embodiment 1, the preheating temperature T_H is set such that the temperature of the target space at the second time ts becomes the target temperature T_M in the first mode of the efficiency priority control. However, in the air conditioning system of the present disclosure, since it is sufficient to achieve a situation in which the target space is heated at the second time ts with higher efficiency than in a case where the target space is heated by operating the air conditioner 11 at a time close to the second time ts, the preheating temperature T_H may be set such that the temperature of the target space at the second time ts becomes higher than the target temperature T_M. In a similar manner, in Embodiment 2, the precooling temperature T_L is set such that the temperature of the target space at the second time ts becomes the target temperature T_M in the first mode of the efficiency priority control. However, in the air conditioning system of the present disclosure, since it is sufficient to achieve a situation in which the target space is cooled at the second time ts with higher efficiency than in a case where the target space is cooled by operating the air conditioner 11 at a time close to the second time ts, the precooling temperature T_L may be set such that the temperature of the target space at the second time ts becomes lower than the target temperature T_M.

(Air conditioning controller)

[0071] FIG. 6 is a schematic configuration diagram of an air conditioning system according to another embodiment.

[0072] The air conditioning system illustrated in FIG. 6 includes a management server 55. The management server 55 is provided at a remote location away from the building in which the air conditioner 11 is installed. The management server 55 includes, for example, a personal computer including a control unit 55a having a calculation unit such as a CPU and a storage such as a ROM and a RAM. The centralized management apparatus 50 and the management server 55 are communicably connected via a network 54 such as the Internet.

[0073] In a case where the air conditioning system includes the management server 55 as in the example illustrated in FIG. 6, instead of the centralized management apparatus 50, the management server 55 may execute the efficiency priority control. In a case where the air conditioning system does not include the centralized management apparatus 50, the outdoor control unit 39 and the indoor control unit 29 may be connected to the management server 55 via the network 54.

[0074] In a case where the air conditioning system does not include the centralized management apparatus 50 and the management server 55, the indoor control unit 29 and/or the outdoor control unit 39 of the air conditioner 11 may execute the efficiency priority control. In this case, the indoor control unit 29 and/or the outdoor control unit 39 of the air conditioner 11 constitute a control unit that executes the efficiency priority control.

[0075] The centralized management apparatus 50, the management server 55, the outdoor control unit 39, or the indoor control unit 29 may be configured to be able to execute both the preheating operation and the precooling operation instead of either the preheating operation or the precooling operation as the first mode of the efficiency priority control. In this case, for example, when the air conditioner 11 performs the heating operation in wintertime, the centralized management apparatus 50 and the like can perform the preheating operation as the first mode, and when the air conditioner 11 performs the cooling operation in summertime, for example, the precooling operation can be performed as the first mode.

[Functional effects of embodiments]

[0076] 

(1) The air conditioning system according to the above embodiment includes the air conditioner 11 that adjusts the temperature of the target space and the air conditioning controller (the centralized management apparatus 50 or the management server 55) that controls the air conditioner 11, and the air conditioning controller 50 or 55 has, as a control mode, the first mode in which the air conditioner 11 is operated in the preheating operation or the precooling operation at or after the first time te set in advance and at or before the second time ts when the target space is used next. The first mode is control of operating the air conditioner 11 and stopping the air conditioner 11 when the temperature of the target space increases to the preheating temperature higher than the target temperature T_M of the target space at the second time ts or when the temperature of the target space decreases to the precooling temperature T_L lower than the target temperature T_M. The preheating temperature T_H is set such that the temperature of the target space becomes the target temperature T_M or a temperature higher than the target temperature T_M at the point of the second time ts due to a decrease of the temperature of the target space after the air conditioner 11 is stopped in the first mode. The precooling temperature T_L is set such that the temperature of the target space becomes the target temperature T_M or a temperature lower than the target temperature T_M at the point of the second time ts by an increase of the temperature of the target space after the air conditioner 11 is stopped in the first mode.

[0077] In general, the air conditioner 11 used in an office or the like performs a schedule operation so as to be operated in a time zone in which the target space is used and to be stopped in a time zone in which the target space is not used. The temperature of the target space gradually decreases or increases from the target temperature (set temperature) T_M of the target space between an end of use of the target space and the next use of the target space. Therefore, the temperature of the target space is closer to the target temperature T_M immediately after the end of use of the target space than immediately before the next use of the target space, and it is advantageous in terms of energy efficiency to operate the air conditioner 11 at that point of time. In the air conditioning system according to the present embodiment, by controlling the air conditioner 11 in the first mode, the temperature of the target space is increased or decreased from a temperature closer to the target temperature T_M than immediately before the second time ts, and thereafter, the temperature of the target space can be brought close to the target temperature T_M by a natural temperature decrease or temperature rise. Therefore, an energy-efficient operation can be performed.

[0078] (2) In the above embodiment, the air conditioning controller 50 or 55 has the second mode as a control mode together with the first mode. In a case where the first mode is a control mode in which the air conditioner 11 performs the preheating operation, the second mode is a control mode in which the air conditioner 11 is operated from a temperature lower than the target temperature T_M of the second time ts to increase the temperature of the target space to the target temperature T_M. In a case where the first mode is a control mode in which the air conditioner 11 performs the precooling operation, the second mode is a control mode in which the air conditioner 11 is operated from a temperature higher than the target temperature T_M of the second time ts to decrease the temperature of the target space to the target temperature T_M. The air conditioning controller 50 or 55 selects and executes either the first mode or the second mode on the basis of a predetermined determination criterion. It is therefore possible to operate the air conditioner 11 in a more appropriate control mode in accordance with the predetermined determination criterion.

[0079] (3) In the above embodiment, the second mode is a control mode of causing the temperature of the target space to reach the target temperature T_M at the second time ts. Alternatively, the second mode can be a control mode in which the air conditioner 11 is operated from the second time ts to cause the temperature of the target space to reach the target temperature T_M. In this case, it is possible to determine which of the preheating operation and precooling operation or the normal heating operation or cooling operation is advantageous in terms of the energy consumption or the electricity charge, and to adopt either of the operations.

[0080] (4) In the above embodiment, the air conditioning controller 50 or 55 executes a control mode of the first mode or the second mode with a lower energy consumption. Therefore, an efficient operation in terms of energy can be performed.

[0081] (5) In the above embodiment, the air conditioning controller 50 or 55 executes a control mode of the first mode or the second mode with a lower electricity charge. Therefore, an efficient operation in terms of cost can be performed.

[0082] (6) In the above embodiment, the air conditioning controller 50 or 55 executes the first mode or the second mode on the basis of an energy consumption obtained in consideration of heat insulation performance in the target space. Since the heat insulation performance of the target space affects the energy consumption, a more appropriate control mode can be executed by considering the heat insulation performance of the target space in obtaining the energy consumption.

[0083] (7) In the above embodiment, the air conditioning controller 50 or 55 executes the first mode or the second mode on the basis of an energy consumption obtained in consideration of a predicted value of an outside temperature at or after the first time te. Since the outside temperature affects the energy consumption, a more appropriate control mode can be executed by considering the predicted value of the outside temperature in obtaining the energy consumption.

[0084] (8) In the above embodiment, the air conditioning controller 50 or 55 executes the first mode or the second mode on the basis of an energy consumption obtained in consideration of a predicted value of a difference between the temperature of the target space and the outside temperature at or after the first time te. Since the difference between the temperature of the target space and the outside temperature affects the energy consumption, a more appropriate control mode can be executed by considering the predicted value of the difference between the temperature of the target space and the outside temperature in obtaining the energy consumption.

[0085] (9) In the above embodiment, the air conditioning controller 50 or 55 executes the first mode and the second mode on the basis of an energy consumption obtained in consideration of necessity of a defrost operation in accordance with a predicted value of the outside temperature. In a case where the outside temperature is in a predetermined temperature range, since the energy consumption is increased by operating the air conditioner 11 in the defrost operation, a more appropriate control mode can be executed by considering necessity of the defrost operation in obtaining the energy consumption.

[0086] (10) In the above embodiment, the first time te is a time at which the air conditioner 11 is stopped in the schedule operation, a time at which the target space is not in use any more, or a time at which no person appears in the target space. In any case, there is a high possibility that no person is in the target space, and it is therefore possible to perform driving with priority given to efficiency.

[0087] (11) The air conditioner 11 according to another embodiment described above includes a control unit (indoor control unit 29 and/or outdoor control unit 39) having, as a control mode, a first mode in which the air conditioner 11 is operated in the preheating operation or the precooling operation at or after the first time te set in advance and at or before the second time ts at which the target space is used next, in which the first mode is control in which the air conditioner 11 is operated and the air conditioner 11 is stopped when the temperature of the target space increases to the preheating temperature T_H higher than the target temperature T_M of the target space at the second time ts or when the temperature of the target space decreases to the precooling temperature T_L lower than the target temperature T_M. The preheating temperature T_H is set such that the temperature of the target space becomes the target temperature T_M or a temperature higher than the target temperature T_M at the point of the second time ts due to a decrease of the temperature of the target space after the air conditioner 11 is stopped in the first mode. The precooling temperature T_L is set such that the temperature of the target space becomes the target temperature T_M or a temperature lower than the target temperature T_M at the point of the second time ts by an increase of the temperature of the target space after the air conditioner 11 is stopped in the first mode.

[0088] In the air conditioner 11 having the above configuration, by controlling the air conditioner in the first mode by the control unit, the temperature of the target space is increased or decreased from a temperature closer to the target temperature T_M than immediately before the second time ts, and thereafter, the temperature of the target space can be brought close to the target temperature T_M by a natural temperature decrease or temperature rise. Therefore, an energy-efficient operation can be performed.

[0089] (12) The air conditioning control method according to the above embodiment is an air conditioning control method of controlling the air conditioner 11 that adjusts the temperature of the target space, the air conditioning control method including operating the air conditioner 11 in a first step at or after a first time set in advance and at or before a second time ts at which the target space is used next, and stopping the air conditioner 11 in a second step when the temperature of the target space increases to a preheating temperature T_H higher than a target temperature of the target space at the second time or decreases to a precooling temperature T_L lower than the target temperature. The preheating temperature T_H is set such that the temperature of the target space becomes the target temperature T_M or a temperature higher than the target temperature T_M at the point of the second time ts due to a decrease of the temperature of the target space after the air conditioner 11 is stopped in the second step. The precooling temperature T_L is set such that the temperature of the target space becomes the target temperature T_M or a temperature lower than the target temperature T_M at the point of the second time ts due to an increase of the temperature of the target space after the air conditioner 11 is stopped in the second step.

[0090] In the air conditioning control method having the above configuration, by controlling the air conditioner 11 in the first mode, the temperature of the target space is increased or decreased from a temperature closer to the target temperature T_M than immediately before the second time ts, and thereafter, the temperature of the target space can be brought close to the target temperature T_M by a natural temperature decrease or temperature rise. Therefore, an energy-efficient operation can be performed.

[0091] The present disclosure should not be limited to the above exemplification, but is intended to include any modification recited in claims within meanings and a scope equivalent to those of the claims.

REFERENCE SIGNS LIST

[0092] 

11:

air conditioner

29:

indoor control unit

39:

outdoor control unit

50:

centralized management apparatus (air conditioning controller)

55:

management server (air conditioning controller)

T_M:

target temperature

T_in:

indoor temperature

T_out:

outdoor temperature

te:

first time

ts:

second time

Claims

1. An air conditioning system comprising:

an air conditioner (11) that adjusts a temperature of a target space; and an air conditioning controller (50, 55) that controls the air conditioner (11), wherein

the air conditioning controller (50, 55) has, as a control mode, a first mode in which the air conditioner (11) performs a preheating operation or a precooling operation at or after a first time (te) set in advance and at or before a second time (ts) at which the target space is used next,

the first mode is control of operating the air conditioner (11) and stopping the air conditioner (11) when the temperature of the target space increases to a preheating temperature (T_H) higher than a target temperature (T_M) of the target space at the second time (ts) or when the temperature of the target space decreases to a precooling temperature (T_L) lower than the target temperature (T_M),

the preheating temperature (T_H) is set such that the temperature of the target space becomes the target temperature (T_M) or higher than the target temperature (T_M) at a point of the second time (ts) due to a decrease of the temperature of the target space after the air conditioner (11) stops in the first mode, and

the precooling temperature (T_L) is set such that the temperature of the target space becomes the target temperature (T_M) or lower than the target temperature (T_M) at the point of the second time (ts) due to an increase of the temperature of the target space after the air conditioner (11) stops in the first mode.

2. The air conditioning system according to claim 1, wherein

the air conditioning controller (50, 55) has a second mode as a control mode together with the first mode,

in a case where the first mode is a control mode in which the air conditioner (11) performs the preheating operation, the second mode is a control mode in which the air conditioner (11) is operated from a temperature lower than the target temperature (T_M) at the second time (ts) to increase the temperature of the target space to the target temperature (T_M),

in a case where the first mode is a control mode in which the air conditioner (11) performs the precooling operation, the second mode is a control mode in which the air conditioner (11) is operated from a temperature higher than the target temperature (T_M) at the second time (ts) to decrease the temperature of the target space to the target temperature (T_M), and

the air conditioning controller (50, 55) selects and executes either the first mode or the second mode based on a predetermined determination criterion.

3. The air conditioning system according to claim 2, wherein the second mode is a control mode of causing the temperature of the target space to reach the target temperature (T_M) at the second time (ts).

4. The air conditioning system according to claim 2, wherein the second mode is a control mode in which the air conditioner (11) is operated from the second time (ts) to cause the temperature of the target space to reach the target temperature (T_M).

5. The air conditioning system according to any one of claims 2 to 4, wherein the air conditioning controller (50, 55) executes a control mode of the first mode or the second mode with a lower energy consumption.

6. The air conditioning system according to any one of claims 2 to 4, wherein the air conditioning controller (50, 55) executes a control mode of the first mode or the second mode with a lower electricity charge.

7. The air conditioning system according to claim 5 or 6, wherein the air conditioning controller (50, 55) executes the first mode or the second mode based on an energy consumption obtained in consideration of heat insulation performance in the target space.

8. The air conditioning system according to any one of claims 5 to 7, wherein the air conditioning controller (50, 55) executes the first mode or the second mode based on an energy consumption obtained in consideration of a predicted value of an outside temperature (T_out) at or after the first time (te).

9. The air conditioning system according to any one of claims 5 to 8, wherein the air conditioning controller (50, 55) executes the first mode or the second mode based on an energy consumption obtained in consideration of a predicted value of a difference between a temperature of the target space (T_in) and the outside temperature (T_out) at or after the first time (te).

10. The air conditioning system according to any one of claims 5 to 9, wherein the air conditioning controller (50, 55) executes the first mode and the second mode based on an energy consumption obtained in consideration of necessity of a defrost operation in accordance with a predicted value of the outside temperature.

11. The air conditioning system according to any one of claims 1 to 10, wherein the first time (te) is a time at which the target space is not in use any more.

12. The air conditioning system according to any one of claims 1 to 10, wherein the first time (te) is a time when the air conditioner (11) is stopped in a schedule operation.

13. The air conditioning system according to any one of claims 1 to 10, wherein the first time (te) is a time at which no person appears in the target space.

14. An air conditioning controller that controls an air conditioner (11) that adjusts a temperature of a target space, wherein

the air conditioning controller has, as a control mode, a first mode in which the air conditioner (11) performs a preheating operation or a precooling operation at or after a first time (te) set in advance and at or before a second time (ts) at which the target space is used next,

the first mode is control of operating the air conditioner (11) and stopping the air conditioner (11) when the temperature of the target space increases to a preheating temperature (T_H) higher than a target temperature (T_M) of the target space at the second time (ts) or when the temperature of the target space decreases to a precooling temperature (T_L) lower than the target temperature (T_M),

the preheating temperature (T_H) is set such that the temperature of the target space becomes the target temperature (T_M) or higher than the target temperature (T_M) at a point of the second time (ts) due to a decrease of the temperature of the target space after the air conditioner (11) stops in the first mode, and

the precooling temperature (T_L) is set such that the temperature of the target space becomes the target temperature (T_M) or lower than the target temperature (T_M) at the point of the second time (ts) due to an increase of the temperature of the target space after the air conditioner (11) stops in the first mode.

15. An air conditioner that adjusts a temperature of a target space, the air conditioner comprising a control unit (29, 39) having, as a control mode, a first mode in which the air conditioner performs a preheating operation or a precooling operation at or after a first time (te) set in advance and at or before a second time (ts) at which the target space is used next, wherein

the first mode is control of operating the air conditioner and stopping the air conditioner (11) when the temperature of the target space increases to a preheating temperature (T_H) higher than a target temperature (T_M) of the target space at the second time (ts) or when the temperature of the target space decreases to a precooling temperature (T_L) lower than the target temperature (T_M),

the preheating temperature (T_H) is set such that the temperature of the target space becomes the target temperature (T_M) or higher than the target temperature (T_M) at a point of the second time (ts) due to a decrease of the temperature of the target space after the air conditioner (11) stops in the first mode, and

the precooling temperature (T_L) is set such that the temperature of the target space becomes the target temperature (T_M) or lower than the target temperature (T_M) at the point of the second time (ts) due to an increase of the temperature of the target space after the air conditioner (11) stops in the first mode.

16. An air conditioning control method of controlling an air conditioner (11) that adjusts a temperature of a target space, the air conditioning control method comprising:

operating the air conditioner (11) in a first step at or after a first time (te) set in advance and at or before a second time (ts) at which the target space is used next; and

stopping the air conditioner (11) in a second step when the temperature of the target space increases to a preheating temperature (T_H) higher than a target temperature (T_M) of the target space at the second time (ts) or decreases to a precooling temperature (T_L) lower than the target temperature (T_M), wherein

the preheating temperature (T_H) is set such that the temperature of the target space becomes the target temperature (T_M) or higher than the target temperature (T_M) at a point of the second time (ts) due to a decrease of the temperature of the target space after the air conditioner (11) stops in the second step, and

the precooling temperature (T_L) is set such that the temperature of the target space becomes the target temperature (T_M) or lower than the target temperature (T_M) at the point of the second time (ts) due to an increase of the temperature of the target space after the air conditioner (11) stops in the second step.

Drawing