Air Conditioning System

Abstract

The air conditioning system comprises: an air conditioner indoor unit provided in an air-conditioned section; an occupancy detection unit that detects occupancy information indicating the presence or absence of a person in the air-conditioned section; and a control unit that, when the occupancy information detected by the occupancy detection unit indicates the absence of a person in the air-conditioned section, changes the operating conditions of the air conditioner indoor unit so that the air conditioning capacity is greater than when the air conditioner indoor unit is operated under the operating conditions set for the air conditioner indoor unit.

Description

air conditioning system

[0001] The present disclosure relates to a building thermal storage type air conditioning system.

[0002] A known air conditioning system of the building thermal storage type prevents an increase in power consumption due to excessive heat storage by calculating the required amount of heat storage from the amount of heat stored on the previous day (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2001-248879

[0004] In such a building thermal storage type air conditioning system, the problem is that the heat storage capacity is small because the system can only store heat up to the set temperature when the target air conditioning zone is used. On the other hand, if the target air conditioning zone is stored with heat up to a temperature that deviates significantly from the set temperature in order to increase the heat storage capacity, the comfort of the users of the target air conditioning zone will be compromised.

[0005] The present disclosure has been made in consideration of the above-mentioned situation, and aims to provide a structural heat storage type air conditioning system that can increase heat storage without compromising the comfort of the target air-conditioned compartment.

[0006] The air conditioning system of the present disclosure comprises an air conditioner indoor unit provided in an air conditioning section, a presence detection unit that detects occupancy information indicating the presence or absence of a person in the air conditioning section, and a control unit that, when the occupancy information detected by the occupancy detection unit indicates the absence of a person in the air conditioning section, changes the operating conditions of the air conditioner indoor unit so that the air conditioning capacity is greater than when the air conditioner indoor unit is operated under the operating conditions set for the air conditioner indoor unit.

[0007] According to the present disclosure, when the presence detection unit indicates that an air-conditioned section is unoccupied, the control unit of the air conditioning system changes the operating conditions of the air conditioner indoor unit to increase capacity. Therefore, the air conditioning system can use the unoccupied air-conditioned section as a heat storage tank, and can store heat in the air-conditioned section without compromising the comfort of the target air-conditioned section.

[0008] Fig. 1 is a schematic diagram showing a building equipped with an air conditioning system according to embodiment 1. Fig. 2 is a flowchart for explaining the operation of an air conditioner indoor unit according to embodiment 1. Fig. 3 is a diagram showing an air conditioner indoor unit in an air conditioning system according to embodiment 2. Fig. 4 is a functional block diagram showing the functions of a control unit in an air conditioning system according to embodiment 2. Fig. 5 is a flowchart of operation control of an air conditioning system according to embodiment 2. Fig. 6 is a functional block diagram showing the functions of a control unit in an air conditioning system according to embodiment 3. Fig. 7 is a flowchart of operation control of an air conditioning system according to embodiment 3. Fig. 8 is a schematic diagram showing a building equipped with an air conditioning system according to embodiment 4.

[0009] Hereinafter, an air conditioning system according to an embodiment will be described with reference to the drawings. In the drawings, identical components are denoted by the same reference numerals, and duplicated descriptions will be given only when necessary. The present disclosure may include any combination of the configurations described in the following embodiments that can be combined.

[0010] Embodiment 1. Fig. 1 is a schematic diagram showing a building B equipped with an air conditioning system 20 according to embodiment 1. As shown in Fig. 1, the air conditioning system 20 includes an air conditioner indoor unit 1, a room occupancy detection unit 2, a control unit 3, and an air conditioning section utilization information accumulation unit 15.

[0011] There are multiple air conditioning sections 14 in building B. An air conditioner indoor unit 1 is provided for each air conditioning section 14. The air conditioner indoor unit 1 performs either cooling operation, in which cooled air is supplied to the air conditioning section 14, or heating operation, in which heated air is supplied. One floor in building B may be one air conditioning section 14, one room may be one air conditioning section 14, or a partial area within one room may be one air conditioning section 14. The air conditioning system 20 of this embodiment is a building thermal storage type air conditioning system 20 that uses one or more air conditioning sections 14 as a thermal storage tank.

[0012] The occupancy detection unit 2 is provided in at least one of the air conditioning sections 14 in which the air conditioner indoor unit 1 is installed. FIG. 1 shows a case where an occupancy detection unit 2 is provided in each of the air conditioning sections 14 in which a person is shown and in which no person is shown. The occupancy detection unit 2 detects occupancy information indicating the presence or absence of a person in the air conditioning section 14. The occupancy detection unit 2 is an infrared sensor, detection information from a card reader, a thermal image sensor, an illuminance sensor, or equipment in the air conditioning section 14. The occupancy detection unit 2 inputs the detected occupancy information to the control unit 3.

[0013] The control unit 3 is communicatively connected to the air conditioner indoor unit 1 to be controlled via a communication line such as the Internet. The control unit 3 controls the air conditioner indoor unit 1. When the occupancy information detected by the occupancy detection unit 2 indicates that no one is present in the air-conditioned section 14, the control unit 3 changes the operating conditions of the air conditioner indoor unit 1 so that the air-conditioning capacity is greater than when the air conditioner indoor unit 1 is operated under the operating conditions set for that air conditioner indoor unit 1. Specifically, when the occupancy information detected by the occupancy detection unit 2 indicates that no one is present in the air-conditioned section 14, the control unit 3 lowers the set temperature of the air-conditioned section 14 of the air conditioner indoor unit 1 during cooling and raises the set temperature of the air conditioner indoor unit 1 during heating.

[0014] When the processing circuit of the control unit 3 is dedicated hardware, the processing circuit may be, for example, a single circuit, a composite circuit, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination of these. Each functional unit realized by the processing circuit may be realized by separate hardware, or each functional unit may be realized by a single piece of hardware. When the processing circuit of the control unit 3 is a CPU, each function executed by the processing circuit is realized by software, firmware, or a combination of software and firmware. The software and firmware are written as programs and stored in the memory unit 109. The CPU realizes each function of the processing circuit by reading and executing the programs stored in the memory unit. Note that some of the functions of the processing circuit may be realized by dedicated hardware, and some may be realized by software or firmware.

[0015] The air-conditioning section usage information accumulation unit 15 accumulates information on the future planned usage of the air-conditioning section 14. The air-conditioning section usage information accumulation unit 15 is communicably connected to the control unit 3 via a communication line such as the Internet. A conference room reservation system or the like may be used as the air-conditioning section usage information accumulation unit 15.

[0016] Operation Next, a description will be given of the operation of the air conditioner indoor unit 1 in the air conditioning system 20 according to embodiment 1. Fig. 2 is a flowchart for explaining the operation of the air conditioner indoor unit 1 according to embodiment 1.

[0017] 2, the presence detection unit 2 detects presence information indicating the presence or absence of a person in the air-conditioned section 14 (step S1). Next, the control unit 3 determines whether the presence information detected by the presence detection unit 2 indicates the absence of a person in the air-conditioned section 14 (step S2).

[0018] The control unit 3 can identify air conditioning sections 14 that are not scheduled for use based on information about future planned use of the air conditioning sections 14 stored in the air conditioning section usage information storage unit 15. The control unit 3 may determine the occupancy information of only the identified air conditioning sections 14 that are not scheduled for use.

[0019] In step S3, if the control unit 3 determines that the presence information detected by the presence detection unit 2 does not indicate that there is no one present in the air conditioning section 14 (NO in step S3), the control unit 3 controls the air conditioner indoor unit 1 to continue air conditioning operation in the air conditioning section 14 in which the presence detection unit 2 is installed (step S4).

[0020] In step S3, if the control unit 3 determines that the presence information detected by the presence detection unit 2 indicates that no one is present in the air conditioning section 14 (YES in step S3), the set temperature of the air conditioning section 14 of the air conditioner indoor unit 1 is lowered during cooling, and the set temperature of the air conditioner indoor unit 1 is raised during heating (step S5).

[0021] The heat stored in the unoccupied air-conditioning compartment 14 is used for air conditioning in the air-conditioning compartment 14 by heat transfer and radiation from the walls between the air-conditioning compartments 14 to the air when the air-conditioning is operated later when someone is present in the room.

[0022] Other examples of changing the operating conditions of the air conditioner indoor unit 1 so that the air conditioning capacity is greater than when the air conditioner indoor unit 1 is operated under the operating conditions set for that air conditioner indoor unit 1 include the following. Specifically, the control unit 3 may start air conditioning operation when the air conditioner indoor unit 1 is not operating in an air conditioning section 14 where it has been confirmed that no one is present. The control unit 3 may also increase the airflow rate of the fan of the air conditioner indoor unit 1 in the air conditioning section 14 where it has been confirmed that no one is present.

[0023] In step S3, the control unit 3 may repeatedly acquire presence information from the presence detection unit 2 during an absence determination period of, for example, 30 minutes to 1 hour, and determine that no one is present when all of the presence information during this absence determination period indicates that no one is present. This allows the control unit 3 to prevent erroneous identification of the presence or absence of a person.

[0024] The control unit 3 may preferentially use, as a heat storage tank, an air conditioning zone 14 that is used less frequently, selected based on past usage information. Specifically, the air conditioning zone usage information accumulation unit 15 accumulates information on the past usage history of the air conditioning zones 14, and the control unit 3 determines the usage frequency of each air conditioning zone 14 based on the accumulated usage history. Then, when the control unit 3 determines that no one is present in multiple air conditioning zones 14 based on the occupancy information from the occupancy detection unit 2, it preferentially operates the air conditioner indoor units 1 of the air conditioning zones 14 that are used less frequently, in accordance with the number of air conditioning zones 14 that corresponds to the required amount of heat storage. By preferentially using the air conditioning zones 14 that are used less frequently as a heat storage tank, the comfort of the occupants of building B is less likely to be impaired.

[0025] If the air conditioning section 14 is scheduled to be used during a period in which power consumption is desired to be reduced, based on information about the future planned use of the air conditioning section 14 stored in the air conditioning section usage information storage section 15, the control section 3 may operate the air conditioner indoor unit 1 before the period in which power consumption is desired to be reduced. Heat is stored in the air conditioning section 14 before the period in which power consumption is desired to be reduced. This makes it possible to reduce power consumption by the air conditioner indoor unit 1 during the period in which power consumption is desired to be reduced.

[0026] According to the air conditioning system 20 of the first embodiment, the operating conditions of the air conditioner indoor unit 1 in an air conditioning section 14 where it has been confirmed that no one is present based on the presence information obtained by the presence detection unit 2 are changed so that the air conditioning capacity is greater than when the air conditioning section 1 is operated under the operating conditions set for that air conditioner indoor unit 1. Therefore, according to the air conditioning system 20 of the first embodiment, cold or hot energy can be stored in an air conditioning section 14 where no one is present. Therefore, the air conditioning section 14 can be used as a heat storage tank without compromising comfort. Furthermore, the cold or hot energy stored in the air conditioning section 14 as a heat storage tank is used for subsequent air conditioning operation of the air conditioning system 20.

[0027] Furthermore, during cooling, the set temperature of the air conditioner indoor unit 1 corresponding to an unoccupied air conditioning section 14 is lowered below the set temperature during cooling when someone is present. During heating, the set temperature of the air conditioner indoor unit 1 corresponding to an unoccupied air conditioning section 14 is raised above the set temperature during heating when someone is present. This makes it possible to increase the amount of heat stored in the unoccupied air conditioning section 14.

[0028] Embodiment 2 In embodiment 2, the operation of the air conditioning system 20 from when it receives a power supply and demand adjustment command to when the power supply and demand adjustment period ends will be described. The "power supply and demand adjustment period" refers to the period during which the power consumption of the air conditioning system 20 is actually adjusted based on the power supply and demand adjustment command. Here, power consumption adjustment during the "power supply and demand adjustment period" can be posiwatt-type adjustment, which increases power consumption, or negawatt-type adjustment, which reduces power consumption. If power consumption is to be increased during the "power supply and demand adjustment period", the air conditioning system 20 performs heat storage operation during the "power supply and demand adjustment period". Furthermore, if power consumption is to be reduced during the "power supply and demand adjustment period", a "power supply and demand adjustment preparation period" is set before the "power supply and demand adjustment period". The "power supply and demand adjustment preparation period" refers to the period during which heat storage operation is performed before the power supply and demand adjustment period.

[0029] In addition, the operation of changing the settings according to whether people are present or absent in the first embodiment is the heat storage operation of the air conditioning system 20 in the above-mentioned "power supply and demand adjustment period" and "power supply and demand adjustment preparation period."

[0030] The configuration of the air conditioning system 20 according to the second embodiment is the same as that of the air conditioning system 20 shown in Fig. 1, and the same parts as those in Fig. 1 will be described with the same reference numerals. Fig. 3 is a diagram showing an air conditioner indoor unit 1 in the air conditioning system 20 according to the second embodiment. As shown in Fig. 2, the air conditioner indoor unit 1 provided in the air-conditioned section 14 has a temperature sensor 30.

[0031] The temperature sensor 30 is connected to the control unit 3 , measures the room temperature of the air-conditioned section 14 , and outputs the measured room temperature to the control unit 3 .

[0032] FIG. 4 is a functional block diagram showing the functions of the control unit 3 in the air conditioning system 20 according to the second embodiment.

[0033] As shown in FIG. 4 , the control unit 3 includes a power supply and demand adjustment command receiving unit 5, a heat load history information storage unit 6, a heat load prediction unit 4, a heat storage allowable amount calculation unit 9, an operation plan creation unit 18, a period operation efficiency calculation unit 17, a power consumption calculation unit 19, and a power supply and demand adjustment allowable amount calculation unit 16.

[0034] The power supply and demand adjustment command receiving unit 5 receives a power supply and demand adjustment command from an external source via a communication line such as the Internet. Based on the received power supply and demand adjustment command, the power supply and demand adjustment command receiving unit 5 acquires the power supply and demand adjustment period, the power adjustment amount, the power adjustment fee, etc. Note that the power supply and demand adjustment command receiving unit 5 may also acquire the power supply and demand adjustment period, the power adjustment amount, the power adjustment fee, etc. from another server, etc., based on the power supply and demand adjustment command.

[0035] The power supply and demand adjustment command is issued by an aggregator, a power company, etc. The power supply and demand adjustment command is, for example, a power supply and demand adjustment command with content such as "keep power usage to 100 kW or less from 4:00 PM to 7:00 PM tomorrow." The power supply and demand adjustment command includes information such as the supply and demand adjustment period, the power adjustment amount, and the power adjustment fee, but some or all of this information may be predetermined in a separate contract, etc. When all of the information in the power supply and demand adjustment command is predetermined in a contract, etc., the power supply and demand adjustment command receiver 5 reads out information that has been stored in advance in a memory (not shown) of the control unit 3.

[0036] The thermal load history information storage unit 6 stores past operating data of the air conditioner indoor unit 1. Here, the operating data includes the thermal load of the air-conditioning section 14, the room temperature of the air-conditioning section 14, or the power consumption, airflow setting, refrigerant temperature, refrigerant pressure, or compressor frequency of the air conditioner indoor unit 1.

[0037] The heat load of the air-conditioned section 14 refers to the amount of heat provided to the air-conditioned section 14 by the air conditioner indoor unit 1 for cooling or heating. The airflow setting of the air conditioner indoor unit 1 refers to the airflow rate of a fan provided in the air conditioner indoor unit 1 and sending cooled or heated air to the air-conditioned section 14. The refrigerant temperature refers to the temperature of the refrigerant in one or more of the compressor, condenser, or evaporator when the air conditioning system 20 uses a refrigeration cycle as a heat source. The refrigerant pressure refers to the pressure of the refrigerant on one or more of the discharge side of the compressor or downstream of the expansion valve when the air conditioning system 20 uses a refrigeration cycle as a heat source. The compressor frequency refers to the drive frequency of the compressor that circulates the refrigerant when the air conditioning system 20 uses a refrigeration cycle as a heat source. In the following, the present embodiment will be described using an example in which the air conditioning system 20 uses a refrigeration cycle as a heat source.

[0038] The thermal load prediction unit 4 predicts the thermal load during the power supply and demand adjustment period. For example, the thermal load prediction unit 4 predicts the thermal load of the air conditioning sections 14 during the power supply and demand adjustment period based on past operating data of the air conditioning system 20 stored in the thermal load history information storage unit 6. The thermal load prediction unit 4 predicts the thermal load of each of the multiple air conditioning sections 14 for each air conditioning section 14.

[0039] Next, a method for measuring the heat load will be described. For example, the heat load can be calculated from the difference between the room temperature of the air-conditioned compartment 14 drawn in by the air conditioner indoor unit 1 and the temperature of the air discharged, and the air volume of the fan. Alternatively, the heat load can be calculated from the difference between the inlet pressure and outlet pressure of the refrigerant of the air conditioner indoor unit 1, and the difference between the inlet temperature and outlet temperature.

[0040] Next, a method for predicting the heat load will be described. The heat load prediction unit 4 stores a database that links accumulated data on heat loads from past operations with the outdoor temperature, amount of solar radiation, occupancy information, room temperature information, humidity information, ventilation heat amount, etc. at that time. The heat load prediction unit 4 predicts the heat load amount by comparing information such as weather forecasts (outdoor temperature, amount of solar radiation) for the time period to be predicted, usage information for the air-conditioned compartments 14, and changes in room temperature with the stored database. This improves the accuracy of the heat load prediction.

[0041] Furthermore, the heat load predicting unit 4 can improve the accuracy of predicting the heat load by using a thermal image of the air-conditioned section 14 obtained by an infrared sensor and sensor information obtained by a humidity sensor.

[0042] Here, the data stored in the heat load history information storage unit 6 is updated using newly obtained heat load data, and prediction accuracy can be improved by performing AI learning.

[0043] The thermal load prediction unit 4 updates the past operating data stored in the thermal load history information storage unit 6 based on the future thermal load predicted by the thermal load prediction unit 4, and performs AI learning, thereby improving the accuracy of thermal load prediction.

[0044] For example, AI learning is used to rank the predicted and measured heat loads to determine which information has the greatest impact on the prediction, and the weighting of the information used in the prediction is adjusted based on the results.

[0045] The heat storage allowance calculation unit 9 calculates the heat storage allowance that can be stored in the air conditioning sections 14 during the power supply and demand adjustment preparation period. The heat storage allowance calculation unit 9 predicts the amount of heat that can be stored from past temperature data and the like for each air conditioning section 14. The heat storage allowance calculation unit 9 can determine this amount from, for example, the heat load when heat storage operation was performed during the power supply and demand adjustment preparation period from past operation data, and how long a predetermined temperature range was maintained in each air conditioning section 14 when the air conditioning system 20 stopped operation or reduced the heat load during the power supply and demand adjustment period.

[0046] The heat storage allowable capacity calculation unit 9 can improve the accuracy of calculating the heat storage allowable capacity by referring to information on the outside temperature, weather information, and the number of occupants of the target air-conditioning section 14, as well as the heat load prediction.

[0047] Next, a method for measuring the amount of heat storage will be described. The heat storage allowable amount calculation unit 9 measures the amount of heat storage in the air-conditioned section 14 from the amount of change in room temperature in response to the heat load applied to the air-conditioned section 14. The heat storage allowable amount calculation unit 9 can improve the accuracy of estimating the amount of heat storage by accumulating data on the amount of change in room temperature in response to the applied heat load from past operating data accumulated in the heat load history information accumulation unit 6.

[0048] Next, a description will be given of a method for calculating the heat storage allowance by the heat storage allowance calculation unit 9. The heat storage allowance calculation unit 9 can calculate the heat storage allowance when the room temperature changes to a target temperature, based on data on the amount of room temperature change in response to past heat loads applied to the air-conditioned section 14, which is stored in the heat load history information storage unit 6. Furthermore, the heat storage allowance calculation unit 9 can improve the accuracy of the heat storage allowance calculated from past operating data and the outdoor temperature, amount of solar radiation, occupancy information, humidity information, and ventilation heat amount at that time.

[0049] The operation plan creation unit 18 creates an operation plan for air conditioning operation and heat storage operation based on the heat load of the air conditioning section 14 during the power supply and demand adjustment period predicted by the heat load prediction unit 4 and the heat storage capacity that can be stored in the air conditioning section 14 during the power supply and demand adjustment preparation period calculated by the heat storage capacity calculation unit 9.

[0050] The period operation efficiency calculation unit 17 calculates the period operation efficiency of the air conditioning operation during the power supply and demand adjustment period and the heat storage operation during the power supply and demand adjustment preparation period when the operation plan created by the operation plan creation unit 18 is executed.

[0051] The periodic operating efficiency calculation unit 17 determines the periodic operating efficiency based on the outdoor air temperature, indoor temperature, indoor unit airflow rate, indoor set temperature, etc., contained in the operating data stored in the thermal load history information storage unit 6. Other influential parameters may include weather forecast data, the amount of solar radiation on the outdoor unit, indoor thermal load (heat exhausted from people and machinery), etc. This allows the operating efficiency for the operating period to be accurately calculated.

[0052] The power consumption calculation unit 19 calculates the amount of power consumption during the power supply and demand adjustment period from the period operating efficiency during the power supply and demand adjustment period calculated by the period operating efficiency calculation unit 17. The power consumption calculation unit 19 also calculates the amount of power consumption during the power supply and demand adjustment preparation period from the period operating efficiency during the power supply and demand adjustment preparation period calculated by the period operating efficiency calculation unit 17. The power consumption calculation unit 19 updates the amounts of power consumption calculated during the power supply and demand adjustment preparation period and the power supply and demand adjustment period.

[0053] The power supply and demand adjustment allowance calculation unit 16 calculates the power supply and demand adjustment allowance amount, which allows power supply and demand adjustment, from the power consumption calculated by the power consumption calculation unit 19. Specifically, the power supply and demand adjustment allowance calculation unit 16 calculates the power supply and demand adjustment allowance amount from the difference between the power consumption calculated by the power consumption calculation unit 19 and the periodic power consumption (predicted value) when operating using a conventional control method. Here, the conventional control method refers to an operation control method in which power supply and demand adjustment is not performed. Furthermore, the power supply and demand adjustment allowance calculation unit 16 can calculate the power supply and demand adjustment allowance amount from temperature information detected by the temperature sensor 30 provided in the air conditioner indoor unit 1 and past operating data of the air conditioner indoor unit 1 stored in the heat load history information storage unit 6. Furthermore, the power supply and demand adjustment allowance calculation unit 16 can accurately calculate the power supply and demand adjustment allowance amount by calculating the power supply and demand adjustment allowance amount from information obtained from the occupancy detection unit 2 and information obtained from the air-conditioning zone utilization information storage unit 15. Therefore, it is possible to prevent a decrease in operating efficiency due to excessive heat storage and a large deviation of the amount of power consumption from the supply and demand adjustment command value.

[0054] The power supply and demand adjustment allowance calculated by the power supply and demand adjustment allowance calculation unit 16 is transmitted to an external party via a communication line such as the Internet.

[0055] 5 is a flowchart of the operation control of the air conditioning system 20 according to embodiment 2. Hereinafter, the operation from when the air conditioning system 20 receives a power adjustment command until the end of the supply and demand adjustment period will be described with reference to FIG.

[0056] The power supply and demand adjustment command receiver 5 receives an external power supply and demand adjustment command via a communication line such as the Internet (step S11). Based on the received power supply and demand adjustment command, the power supply and demand adjustment command receiver 5 acquires the power supply and demand adjustment period, the power adjustment amount, the power adjustment fee, etc.

[0057] Next, the heat load prediction unit 4 predicts the heat load of the air-conditioned section 14 during the power supply and demand adjustment period based on past operating data of the air-conditioning system 20 stored in the heat load history information storage unit 6 (step S12). Next, the heat storage allowable amount calculation unit 9 calculates the heat storage allowable amount that can be stored in the air-conditioned section 14 during the power supply and demand adjustment preparation period (step S13).

[0058] Next, the operation plan creation unit 18 creates an operation plan for air conditioning operation and heat storage operation based on the heat load of the air conditioning section 14 during the power supply and demand adjustment period predicted by the heat load prediction unit 4 and the heat storage capacity that can be stored in the air conditioning section 14 during the power supply and demand adjustment preparation period calculated by the heat storage capacity calculation unit 9 (step S14).

[0059] Next, the period operating efficiency calculation unit 17 calculates the period operating efficiency of the air conditioning operation during the power supply and demand adjustment period and the heat storage operation during the power supply and demand adjustment preparation period when the operation plan created by the operation plan creation unit 18 is executed (step S15).

[0060] Next, the power consumption calculation unit 19 calculates the amount of power consumption from the period operation efficiency calculated by the period operation efficiency calculation unit 17 (step S16). The power supply and demand adjustment allowance calculation unit 16 calculates the power supply and demand adjustment allowance during the power supply and demand adjustment period from the amount of power consumption calculated by the power consumption calculation unit 19 (step S17).

[0061] Next, the air conditioning system 20 starts power supply and demand adjustment air conditioning and heat storage operation (step S18).

[0062] After the operation starts, the control unit 3 periodically updates the predicted value of the heat load, the weather forecast data, the air-conditioning section utilization information, and the calculated power consumption (predicted value) (step S19).

[0063] Next, the control unit 3 determines whether the updated power consumption amount is smaller than the initial predicted power amount (threshold value) (step S20).

[0064] If the updated power consumption amount is smaller than the initial predicted power amount (YES in step S20), the control unit 3 determines whether the power supply and demand adjustment period has expired (step S22). If the power supply and demand adjustment period has expired (YES in step S22), the control unit 3 ends the process. If the power supply and demand adjustment period has not expired (NO in step S22), the control unit 3 continues operation and returns to the process in step S19.

[0065] On the other hand, in step S20, if the updated power consumption is equal to or greater than the initially predicted power consumption (NO in step S20), the control unit 3 performs power saving operation such as setting an upper limit on the compressor frequency to cut peak power (step S21), and then returns to step S19. That is, after starting power saving operation, the control unit 3 periodically updates the calculated power consumption and repeatedly compares it with the initially predicted power consumption.

[0066] After the power supply and demand adjustment period ends, the obtained data is used as learning data to be referenced when creating the next power supply and demand adjustment air conditioning and heat storage operation plan (step S14).

[0067] Therefore, the air conditioning system 20 according to the second embodiment can execute an operation plan corresponding to an external power supply and demand adjustment command.

[0068] The power consumption calculation unit 19 updates the amount of power consumption calculated during the power supply and demand adjustment preparation period and the power supply and demand adjustment period. If the calculated amount of power consumption is equal to or greater than the threshold, power saving operation is started.

[0069] As a result, with the air conditioning system 20 according to the second embodiment, if the power supply and demand adjustment request is of the posiwatt type, which increases power consumption, heat storage operation is performed in addition to air conditioning operation during the power supply and demand adjustment period, thereby increasing the amount of power consumption. The heat stored during the power supply and demand adjustment period is used in the air conditioning section 14 after the power supply and demand adjustment period ends. Furthermore, if the power supply and demand adjustment request is of the negawatt type, which reduces power consumption, heat storage operation is performed in addition to air conditioning operation during the supply and demand adjustment preparation period, and the stored heat is used to perform air conditioning operation during the power supply and demand adjustment period, thereby reducing the amount of power consumption. In this heat storage operation, the air conditioning capacity is adjusted based on information about the presence of people in the air conditioning section 14, as described in the first embodiment.

[0070] In addition, if the updated power consumption during the power supply and demand adjustment period or the power supply and demand adjustment preparation period is greater than the initial predicted power consumption (threshold), power-saving operation is performed, thereby reducing the power consumption of the air conditioning system 20.

[0071] Furthermore, according to the second embodiment, the operation of the air conditioning system 20 during the power supply and demand adjustment period and the power supply and demand adjustment preparation period can also be controlled in light of the monetary compensation (e.g., an incentive such as a discount on the electricity bill) that can be obtained by complying with the power supply and demand adjustment command. Each functional unit of the control unit 3 can determine the operating conditions during the power supply and demand adjustment period and the power supply and demand adjustment preparation period so as to allow a decrease in efficiency compared to conventional control of the air conditioning system 20, within a range that does not impair the compensation (threshold) that can be obtained by complying with the power supply and demand adjustment command. According to the second embodiment, an optimal control algorithm can be selected depending on economic efficiency, demand response capability, and purpose.

[0072] Third Embodiment In a third embodiment, the periodic operating efficiency of the air conditioning system 20 is improved by determining the thermal storage priority order.

[0073] Fig. 6 is a functional block diagram showing the functions of the control unit 3 in the air conditioning system 20 according to embodiment 3. Note that the same parts as in Fig. 4 are given the same reference numerals, and only the newly shown heat release amount prediction unit 21 and heat storage priority setting unit 8 will be described here.

[0074] The heat release amount prediction unit 21 calculates and predicts the amount of heat release to the outside from each air-conditioning section 14. The heat release amount prediction unit 21 calculates the amount of heat release when the minimum amount of heat is stored in each air-conditioning section that is the heat storage target. The heat release amount is calculated from the temperature change in the room temperature of the target air-conditioning section 14.

[0075] Here, the temperature change is measured using data from a temperature sensor 30 provided in the air conditioner indoor unit 1 or a temperature sensor 30 provided separately in the air-conditioned section 14 .

[0076] Furthermore, by combining the temperature data with weather forecast data such as outside temperature and solar radiation amount, or usage information of the air-conditioned section 14, the accuracy of predicting the amount of heat dissipation can be improved.

[0077] The heat storage priority setting unit 8 determines the heat storage priority of each air conditioning zone 14 based on the heat radiation amount of each air conditioning zone 14 predicted by the heat radiation amount prediction unit 21 and the period operating efficiency of the heat storage operation of the air conditioning zone 14 calculated by the period operating efficiency calculation unit 17. Furthermore, the heat storage priority setting unit 8 calculates the heat storage priority and the heat storage amount of each air conditioning zone 14 from the operating efficiency of the heat storage operation of each air conditioning zone 14 calculated by the period operating efficiency calculation unit 17 and the heat radiation amount prediction result of each air conditioning zone 14 predicted by the heat radiation amount prediction unit 21. The heat storage priority can be set in advance as well as based on the operating efficiency.

[0078] The procedure for setting the thermal storage priority order will be described below. Fig. 7 is a flowchart of the operation control of the air conditioning system 20 according to the third embodiment.

[0079] First, a heat storage target is extracted from the occupancy information obtained by the occupancy detection unit 2 and future use information of the air conditioning section 14 obtained by the air conditioning section use information accumulation unit 15 (step S30). Here, the heat storage target is the air conditioning section 14 having the air conditioner indoor unit 1.

[0080] Next, a threshold value for the periodic operating efficiency during the thermal storage operation is determined (step S31), which serves as an index for determining the ratio between the total amount of thermal storage in the determined thermal storage target sections and the amount of thermal storage to be stored in each thermal storage target. Here, the threshold value for the operating efficiency is a lower limit value for the operating efficiency set to determine the allowable amount of thermal storage in the thermal storage operation. The allowable amount of thermal storage is calculated in the subsequent steps within a range not below this lower limit value.

[0081] Next, the heat radiation amount predicting unit 21 calculates the amount of heat radiation when the minimum amount of heat is stored in each air-conditioning section 14 (step S32).

[0082] Next, the operating efficiency of each air conditioning section 14 during heat storage is calculated from the calculated heat radiation amount and past operating data stored in the heat load history information storage unit 6 (step S33). The operating efficiency can be found from the calculated heat radiation amount of each air conditioning section 14 and the heat load during heat storage required in each air conditioning section 14. The initial value of the heat storage amount given as a condition is provisionally given based on past performance data, etc.

[0083] Next, the heat storage priority order is determined in descending order of the calculated operating efficiency of each air conditioning section 14 (step S34).

[0084] Next, the ratio of the heat storage amounts of the air-conditioning sections 14 is changed so as to maximize the periodic operating efficiency (step S35). Here, the periodic operating efficiency is the operating efficiency of all target sections of the air conditioning system 20 during the calculation period.

[0085] Next, it is determined whether the determined periodic operating efficiency is smaller than a threshold value (step S36). Here, the periodic operating efficiency is the operating efficiency during the heat storage operation.

[0086] Next, if the calculated periodic operating efficiency is equal to or greater than the threshold value (NO in step S36), there is still heat storage capacity, so the total heat storage amount is increased (step S37), and the process returns to step S32 to calculate the heat release amount again. If the periodic operating efficiency is smaller than the threshold value (YES in step S36), the determination of the heat storage priority order is terminated.

[0087] The control unit 3 performs processing in accordance with the set heat storage priority order. Specifically, the heat load prediction unit 4, heat storage allowable amount calculation unit 9, operation plan creation unit 18, period operation efficiency calculation unit 17, power consumption calculation unit 19, power supply and demand adjustment allowable amount calculation unit 16, and heat radiation amount prediction unit 21 of the control unit 3 perform heat storage operation in the air conditioning zones 14 in accordance with the set heat storage priority order. When the occupancy information or the usage information of the air conditioning zones 14 is updated during the heat storage operation, the heat storage priority order is updated.

[0088] According to the air conditioning system 20 of the third embodiment, the operating efficiency during the heat storage operation can be improved and power consumption can be reduced. Furthermore, the priority of the heat storage operation of each air conditioning section 14 is determined using the operating efficiency according to the heat radiation amount of each air conditioning section 14. For example, an air conditioning section 14 that does not face the outdoors has a high priority for the heat storage operation because it radiates less heat outdoors, and an air conditioning section 14 that faces the outdoors and radiates more heat outdoors has a low priority for the heat storage operation. This makes it possible to reduce heat radiation loss from the air conditioning section 14 and improve the periodic operating efficiency of the air conditioning system 20.

[0089] Here, the air conditioning section 14 to be subjected to heat storage can be the walls, ceiling and floor of the air conditioning section 14 in which the air conditioner indoor unit 1 is installed, a heat storage tank provided separately from these, or the building structure surrounding the walls of the air conditioning section 14, etc.

[0090] Here, the thermal storage priority order may be set in advance, which allows for a quick response to an external supply and demand adjustment command.

[0091] Here, by setting the threshold value of the periodic operating efficiency to the periodic operating efficiency during non-thermal storage operation, the amount of power consumption can be reduced compared to during non-thermal storage operation.

[0092] Here, by determining the threshold value of the periodic operating efficiency from the monetary compensation obtained by responding to the power supply and demand adjustment, it is possible to perform air conditioning operation with high cost performance.

[0093] Embodiment 4 Fig. 8 is a schematic diagram showing a building equipped with an air conditioning system 20 according to embodiment 4. The air conditioning system 20 of embodiment 4 uses a refrigeration cycle as a heat source.

[0094] An air conditioning system 20 according to a fourth embodiment includes at least one multi-air conditioner in which multiple air conditioner indoor units 1 are connected to one air conditioner outdoor unit 10 via a refrigerant relay unit 22. The air conditioner outdoor unit 10, the refrigerant relay unit 22, and the air conditioner indoor units 1 are connected to one another via piping, and refrigerant circulates through this piping. The air conditioner outdoor unit 10 is provided with a heat exchanger that exchanges heat between the refrigerant and air. The refrigerant relay unit 22 is provided with a flow path switching device that switches the flow path of the refrigerant heading to each of the multiple air conditioner indoor units 1. When the flow path switching device is switched by the control unit 3, the heat exchanger provided in the air conditioner indoor unit 1 functions as a refrigerant condenser or evaporator.

[0095] When the amount of heat stored by building thermal storage using the air-conditioning section 14 is greater than the required heat load, the control section 3 uses the air heat exchanger of the air conditioner indoor unit 1 of the air-conditioning section 14 where no one is present as a condenser or evaporator. Specifically, if the air conditioner indoor unit 1 of the air-conditioning section 14 where no one is present is referred to as the first indoor unit and the air conditioner indoor unit 1 of the air-conditioning section 14 where no one is present is referred to as the second indoor unit, when performing cooling operation with the first indoor unit, the control section 3 controls the flow path switching device of the refrigerant relay unit 22 to cause the air heat exchanger provided in the second indoor unit to function as a condenser. When performing heating operation with the first indoor unit, the control section 3 controls the flow path switching device of the refrigerant relay unit 22 to cause the air heat exchanger provided in the second indoor unit to function as an evaporator.

[0096] The air conditioning system 20 of the fourth embodiment can also be used in the first, second, and third embodiments.

[0097] Therefore, with the air conditioning system 20 according to the fourth embodiment, the stored heat can be transferred faster than heat transfer by thermal conduction through the wall surfaces of the room. If the heat load during the power supply and demand adjustment period becomes larger than initially expected, air at a temperature lower than the outside air temperature can be used as a heat source, thereby reducing power consumption during the power supply and demand adjustment period.

[0098] The embodiments are presented as examples and are not intended to limit the scope of the claims. The embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the embodiments. These embodiments and their modifications are included within the scope and spirit of the embodiments. Furthermore, embodiments 1 to 3 are applicable to air conditioning systems that use an electric heater or a gas furnace as a heat source, in addition to air conditioning systems that use a refrigeration cycle as a heat source.

[0099] 1 Air conditioner indoor unit, 2 Occupancy detection unit, 3 Control unit, 4 Heat load prediction unit, 5 Power supply and demand adjustment command receiving unit, 6 Heat load history information storage unit, 7 Required heat storage amount calculation unit, 8 Heat storage priority setting unit, 9 Heat storage allowance calculation unit, 10 Air conditioner outdoor unit, 11 Refrigerant distributor, 12 Room use reservation information storage unit, 13 Heat storage tank, 14 Air conditioning section, 15 Air conditioning section use information storage unit, 16 Power supply and demand adjustment allowance calculation unit, 17 Period operating efficiency calculation unit, 18 Operation plan creation unit, 19 Power consumption calculation unit, 20 Air conditioning system, 21 Heat radiation amount prediction unit, 22 Refrigerant relay unit, 30 Temperature sensor, B Building.

Claims

1. An air conditioning system comprising: an air conditioner indoor unit provided in an air conditioning section; a presence detection unit that detects occupancy information indicating the presence or absence of a person in the air conditioning section; and a control unit that, when the occupancy information detected by the occupancy detection unit indicates the absence of a person in the air conditioning section, changes the operating conditions of the air conditioner indoor unit so that the air conditioning capacity is greater than when the air conditioner indoor unit is operated under the operating conditions set for the air conditioner indoor unit.

2. The air conditioning system of claim 1, wherein when the occupancy information indicates that no one is present in the air-conditioning section, the control unit lowers the set temperature of the air conditioner indoor unit in the air-conditioning section when cooling, and raises the set temperature of the air conditioner indoor unit in the air-conditioning section when heating.

3. An air conditioning system as claimed in claim 1 or 2, comprising a heat load history information storage unit that stores operating data of the air conditioner indoor unit, wherein the control unit comprises: a heat load prediction unit that predicts the heat load of the air conditioning unit during a power supply and demand adjustment period, which is a period during which power consumption is actually adjusted based on the operating data of the air conditioning unit stored in the heat load history information storage unit and a power supply and demand adjustment command; a heat storage allowance calculation unit that calculates the heat storage allowance that can be stored in the air conditioning unit during a power supply and demand adjustment preparation period, which is a period during which heat storage operation is performed before the power supply and demand adjustment period; and an operation plan creation unit that creates operation plans for air conditioning operation and heat storage operation based on the heat load of the air conditioning unit during the power supply and demand adjustment period predicted by the heat load prediction unit and the heat storage allowance that can be stored in the air conditioning unit during the power supply and demand adjustment preparation period calculated by the heat storage allowance calculation unit.

4. An air conditioning system according to claim 3, further comprising: a periodic operating efficiency calculation unit that calculates periodic operating efficiencies of the air conditioning operation during the power supply and demand adjustment period and the heat storage operation during the power supply and demand adjustment preparation period when the operation plan created by the operation plan creation unit is executed; and a power consumption calculation unit that calculates the amount of power consumption during the power supply and demand adjustment period from the periodic operating efficiencies calculated by the periodic operating efficiency calculation unit.

5. An air conditioning system as described in claim 3 or 4, further comprising a power supply and demand adjustment command receiving unit that receives the power supply and demand adjustment command, and wherein the heat load prediction unit obtains the power supply and demand adjustment period from the power supply and demand adjustment command received by the power supply and demand adjustment command receiving unit.

6. An air conditioning system as described in claim 4, further comprising a power supply and demand adjustment allowance calculation unit that calculates a power supply and demand adjustment allowance, which is the amount of power that can be adjusted for power supply and demand during the power supply and demand adjustment period, from the amount of power consumption calculated by the power consumption calculation unit.

7. An air conditioning system as described in claim 4 or 6, wherein there are a plurality of air conditioning sections, and the system comprises a heat dissipation amount prediction unit that calculates the amount of heat dissipated to the outside of the air conditioning section, and a heat storage priority setting unit that determines the heat storage priority of the plurality of air conditioning sections based on the heat dissipation amount of the air conditioning section calculated by the heat dissipation amount prediction unit and the period operating efficiency in the heat storage operation of the air conditioning section calculated by the period operating efficiency calculation unit, and the control unit performs air conditioning operation for the plurality of air conditioning sections based on the priority determined by the heat storage priority setting unit.

8. The air conditioning system according to any one of claims 1 to 7, wherein the air conditioner indoor units have a first indoor unit equipped with a heat exchanger and a second indoor unit equipped with a heat exchanger, and when one of the first indoor unit or the second indoor unit performs cooling operation, the heat exchanger of the other indoor unit functions as a condenser, and when one of the first indoor unit or the second indoor unit performs heating operation, the heat exchanger of the other indoor unit functions as an evaporator.

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