Air conditioning system, control method for air conditioning system, and program

Abstract

This air conditioning system comprises: an outdoor unit; a plurality of indoor units that are each provided with a heat exchanger connected to the outdoor unit via a medium circuit through which a heat medium flows, and that each exchange heat between indoor air and the heat medium which is supplied from a compressor via the medium circuit; an outdoor temperature sensor that detects the outdoor temperature where the outdoor unit is installed; an outdoor unit control device that controls operation of the outdoor unit; and indoor unit control devices that are provided to the plurality of indoor units and that control the operation of the indoor units in accordance with set temperatures which are set externally. The outdoor unit control device includes a setting unit that, on the basis of correlation information which indicates a correlation of a reference pressure saturation temperature and outdoor temperatures and which is set in advance, acquires, as a reference pressure saturation temperature, a pressure saturation temperature corresponding to the outdoor temperature detected by the outdoor temperature sensor, and that, on the basis of the acquired reference pressure saturation temperature, sets a target pressure saturation temperature for adjusting output of the compressor.

Description

Air conditioning system, air conditioning system control method, and program

[0001] This application claims priority to Japanese Patent Application No. 2023-176452, filed on October 12, 2023, the contents of which are incorporated herein by reference.

[0002] In an air conditioning system in which multiple indoor units are connected to one outdoor unit, the rotation speed of the compressor installed in the outdoor unit is controlled to supply medium according to the air conditioning load requirement level exerted by each indoor unit (see, for example, Patent Document 1).

[0003] International Publication No. 2014 / 103028

[0004] However, the load demand levels from the multiple indoor units may vary depending on the environment of the room in which each indoor unit is installed, the preferences of the room users, and other factors. Therefore, the outdoor unit operates its compressor to supply medium to the multiple indoor units with a sufficient margin relative to the load demand levels from the multiple indoor units. From the perspective of the indoor units, this results in the supply of medium with a significantly higher capacity relative to the load demand levels. As a result, the temperature difference between the medium circulating through the heat exchanger of the indoor unit and the room temperature becomes large, and adjusting the room temperature to the set temperature requires intermittent ON / OFF heat exchange in the heat exchanger. This results in frequent fluctuations in the room temperature, making it difficult to stably adjust the room temperature to the set temperature. Furthermore, the outdoor unit must output with a sufficient margin relative to the load demand levels from the multiple indoor units, leaving room for improvement in operating efficiency.

[0005] The present disclosure has been made to solve the above-mentioned problems, and aims to provide an air conditioning system, a control method for an air conditioning system, and a program that can improve operating efficiency while more precisely adjusting the temperature in the indoor unit.

[0006] In order to solve the above problem, an air conditioning system according to the present disclosure includes an outdoor unit equipped with a compressor that compresses a heat medium, a plurality of indoor units connected to the outdoor unit via a medium circuit through which the heat medium flows and equipped with a heat exchanger that exchanges heat between the heat medium supplied from the compressor via the medium circuit and indoor air, an outdoor temperature sensor that detects the temperature outside the room where the outdoor unit is installed, an outdoor unit control device that controls the operation of the outdoor unit, and an indoor unit control device that is provided in each of the plurality of indoor units and controls the operation of the indoor unit in accordance with a set temperature that is set externally, wherein the outdoor unit control device includes a setting unit that acquires, as a reference pressure saturation temperature, a pressure saturation temperature that corresponds to the outdoor temperature detected by the outdoor temperature sensor based on predetermined correlation information that indicates a correlation between the outdoor temperature and a reference pressure saturation temperature, and sets a target pressure saturation temperature for adjusting the output of the compressor based on the acquired reference pressure saturation temperature.

[0007] The control method for an air conditioning system according to the present disclosure is a control method for an air conditioning system including an outdoor unit equipped with a compressor and a plurality of indoor units, and obtains a pressure saturation temperature corresponding to a detected outdoor temperature as a reference pressure saturation temperature based on predetermined correlation information indicating the correlation between the outdoor temperature and a reference pressure saturation temperature, and sets a target pressure saturation temperature for adjusting the output of the compressor based on the obtained reference pressure saturation temperature.

[0008] The program according to the present disclosure causes a computer of an air conditioning system including an outdoor unit with a compressor and a plurality of indoor units to execute a process of acquiring a pressure saturation temperature corresponding to a detected outdoor temperature as a reference pressure saturation temperature based on predetermined correlation information indicating the correlation between the outdoor temperature and a reference pressure saturation temperature, and setting a target pressure saturation temperature for adjusting the output of the compressor based on the acquired reference pressure saturation temperature.

[0009] According to the air conditioning system, control method for an air conditioning system, and program of the present disclosure, it is possible to improve operational efficiency while performing more precise temperature adjustment in the indoor units.

[0010] 1 is a diagram illustrating a configuration of an air conditioning system according to an embodiment of the present disclosure. FIG. 2 is a functional block diagram of an indoor control device of the air conditioning system. FIG. 3 is a functional block diagram of an outdoor control device of the air conditioning system. FIG. 4 is an example of correlation information showing the correlation between outdoor temperature and reference pressure saturation temperature during cooling operation. FIG. 5 is a diagram illustrating examples of upper limit values ​​of multiple stages of pressure saturation temperature according to energy saving levels during cooling operation. FIG. 6 is a flowchart illustrating the procedure of a control method in the outdoor control device. FIG. 7 is an example of correlation information showing the correlation between outdoor temperature and reference pressure saturation temperature during heating operation. FIG. 8 is a diagram illustrating examples of upper limit values ​​of multiple stages of pressure saturation temperature according to energy saving levels during heating operation.

[0011] Hereinafter, an embodiment for carrying out an air conditioning system, an air conditioning system control method, and a program according to the present disclosure will be described with reference to the accompanying drawings. However, the present disclosure is not limited to this embodiment. (Configuration of Air Conditioning System) As shown in Figure 1, the air conditioning system 1 includes one outdoor unit 2 and multiple indoor units 3.

[0012] (Configuration of Outdoor Unit) The outdoor unit 2 is installed outside the building. The outdoor unit 2 is connected to a plurality of indoor units 3 via connection pipes 5. The outdoor unit 2 includes a compressor 21, a condenser (not shown), a fan (not shown), an expansion valve (not shown), a switching valve (not shown), an outdoor temperature sensor 25, a pressure sensor 27, and an outdoor unit control device 50.

[0013] The compressor 21, condenser, fan, expansion valve, and switching valve are provided on a medium circuit (not shown). The compressor 21 compresses the heat medium (so-called refrigerant) flowing in the heat medium piping that makes up the medium circuit. The condenser exchanges heat between the outdoor air and the heat medium flowing in the heat medium piping. The fan sends the outside air toward the condenser. The expansion valve expands the heat medium that has passed through the condenser. The switching valve switches the flow of the heat medium in the medium circuit to switch between cooling operation and heating operation.

[0014] The outdoor temperature sensor 25 detects the temperature outside (outdoors) where the outdoor unit 2 is installed. The pressure sensor 27 detects the pressure of the heat medium in the compressor 21. The pressure sensor 27 includes an intake-side sensor 27a that detects the pressure of the heat medium on the intake side of the compressor 21 during cooling operation, and a discharge-side sensor 27b that detects the pressure of the heat medium on the discharge side of the compressor 21 during heating operation.

[0015] (Configuration of indoor unit) The multiple indoor units 3 are installed in the rooms of the building. Each indoor unit 3 performs cooling operation, heating operation, etc. to condition the air in the room. Each indoor unit 3 performs cooling operation, heating operation, etc. to condition the air in the room. The indoor unit 3 includes a heat exchanger (evaporator) 33, an indoor temperature sensor 31, a humidity sensor 32, and an indoor unit control device 40.

[0016] The evaporators 33 of the multiple indoor units 3 are connected to one outdoor unit 2 via a connecting pipe 5. The connecting pipe 5 constitutes a part of a medium circuit (not shown).

[0017] The indoor temperature sensor 31 detects the temperature in the room where the indoor unit 3 is installed. The humidity sensor 32 detects the humidity in the room where the indoor unit 3 is installed.

[0018] The outdoor unit control device 50 of the outdoor unit 2 and the indoor unit control devices 40 of each of the plurality of indoor units 3 are electrically connected via signal lines (not shown).

[0019] (Configuration of indoor unit control device) The indoor unit control device 40 can be configured using a computer such as a microcomputer or a CPU (Central Processing Unit), and hardware such as peripheral circuits and devices of the computer. In this embodiment, the indoor unit control device 40 is configured by a control board on which a microcomputer is mounted. The indoor unit control device 40 controls the operation of the indoor unit 3 in accordance with the set temperature and other settings that are externally set. As shown in FIG. 2 , the indoor unit control device 40 has a functional configuration that is a combination of hardware and software such as a program executed by a computer, and includes an information acquisition unit 41, an external input acceptance unit 42, an operation control unit 43, and an output unit 46.

[0020] The information acquisition unit 41 acquires information on the indoor temperature detected by the indoor temperature sensor 31 and the humidity detected by the humidity sensor 32 .

[0021] The external input receiving unit 42 is capable of receiving a selection from a plurality of operation modes based on a user input from an external remote controller 38, etc. The external input receiving unit 42 receives an input of a set temperature based on a user input from an external remote controller 38, etc.

[0022] The indoor unit 3 allows a user of the air conditioning system 1 to select from a plurality of operation modes, such as heating operation and cooling operation, using a remote controller 38 of the indoor unit 3 or the like. Furthermore, the indoor unit 3 allows a user to select from a plurality of energy-saving levels as the operation mode of the indoor unit 3 using a remote controller 38 of the indoor unit 3 or the like. For example, in this embodiment, the indoor unit 3 has four energy-saving levels set for operation: Lv1: Eco mode Low, Lv2: Eco mode Medium, Lv3: Eco mode High, and Lv4: Eco mode Super High. These four energy-saving levels are set in the order of Lv1: Eco mode Low, Lv2: Eco mode Medium, Lv3: Eco mode High, and Lv4: Eco mode Super High, with the energy-saving levels increasing in this order. In other words, these four energy saving levels are set in the order of decreasing capacity requirement level for the outdoor unit 2: Lv1: Eco mode Low, Lv2: Eco mode Medium, Lv3: Eco mode High, Lv4: Eco mode Super High.

[0023] When the external input receiving unit 42 receives that an operation mode such as heating operation or cooling operation has been selected, it notifies the operation control unit 43 of the selected operation mode. When the external input receiving unit 42 receives that any one of Lv1: Eco mode Low, Lv2: Eco mode Medium, Lv3: Eco mode High, and Lv4: Eco mode Super High has been selected as the energy saving level setting for energy saving operation, it notifies the operation control unit 43 of the type of the selected energy saving level.

[0024] Based on the acquired indoor temperature and humidity, the operation control unit 43 controls the operation of the indoor unit 3. Based on the set temperature, the indoor temperature detected by the indoor temperature sensor 31, and the indoor humidity detected by the humidity sensor 32, the operation control unit 43 controls the indoor unit 3 so that the indoor temperature approaches the set temperature within a predetermined humidity range.

[0025] The output unit 46 outputs the value of the set temperature Ts set in the indoor unit 3 to the outdoor unit control device 50. Furthermore, when an energy saving level (Lv1 to Lv4) is set in the indoor unit 3, the output unit 46 outputs the set level (Lv1 to Lv4) to the outdoor unit control device 50.

[0026] (Configuration of Outdoor Unit Control Device) The outdoor unit control device 50 can be configured using a computer such as a microcomputer or a CPU (Central Processing Unit), and hardware such as peripheral circuits and devices of the computer. In this embodiment, the outdoor unit control device 50 is configured by a control board on which a microcomputer is mounted. The outdoor unit control device 50 controls the operation of the compressor 21 of the outdoor unit 2 in accordance with the capacity requests from the multiple indoor units 3. As shown in FIG. 3 , the outdoor unit control device 50 has a functional configuration that is a combination of hardware and software such as a program executed by the computer, and includes an acquisition unit 51, a setting unit 52, a compressor control unit 53, and a storage unit 54.

[0027] The acquisition unit 51 acquires the value of the set temperature Ts set in each indoor unit 3. Furthermore, if an energy saving level (Lv1 to Lv4) is set, the acquisition unit 51 acquires the set level (Lv1 to Lv4). Furthermore, the acquisition unit 51 acquires the outdoor temperature Ta detected by the outdoor temperature sensor 25 and the pressure of the heat medium in the compressor 21 detected by the pressure sensor 27.

[0028] The setting unit 52 sets a target pressure saturation temperature ST for adjusting the output of the compressor 21. To set the target pressure saturation temperature ST, the setting unit 52 first acquires a pressure saturation temperature corresponding to the outdoor temperature detected by the outdoor temperature sensor 25 as a reference pressure saturation temperature ST1. The storage unit 54 stores correlation information indicating the correlation between the outdoor temperature Ta and the reference pressure saturation temperature. FIG. 4 shows an example of correlation information D1 indicating the correlation between the outdoor temperature Ta and the reference pressure saturation temperature during cooling operation. The setting unit 52 references the correlation information D1 stored in the storage unit 54, as shown in FIG. 4, and acquires the reference pressure saturation temperature ST1 corresponding to the outdoor temperature Ta at that time. Here, when the outdoor temperature Ta is within a temperature range where people can comfortably live, such as 17 to 23°C, the reference pressure saturation temperature ST1 is set to a temperature T1 higher than a temperature T2 (described below). Furthermore, when the outdoor temperature Ta is, for example, 23°C or higher, which is within the temperature range where people feel hot, the standard pressure saturation temperature ST1 gradually decreases from temperature T1 as the outdoor temperature Ta increases, and for example, when the outdoor temperature Ta is 42°C or higher, it is set to temperature T2, which is lower than temperature T1.

[0029] Here, when acquiring the reference pressure saturation temperature ST1, if the detection unit of the outdoor temperature Ta is, for example, accurate to two decimal places or more, the setting unit 52 preferably quantizes the detected value to reduce the processing load. For example, if the detected outdoor temperature Ta is 0 or greater, the setting unit 52 quantizes the value in increments of 0.5 as follows: if the value in the first decimal place is "0, 1, 2, 3, 4," the quantized value in the first decimal place is "0.0"; if the value in the first decimal place is "5, 6, 7, 8, 9," the quantized value in the first decimal place is "0.5"; if the value is negative, the quantized value in the first decimal place is "0, 1, 2, 3, 4," the quantized value in the first decimal place is "-0.5"; and if the value in the first decimal place is "5, 6, 7, 8, 9," the quantized value in the first decimal place is "-1.0." For example, if the detected value of the outdoor temperature Ta is "27.36", the quantized value will be "27.0". For example, if the detected value of the outdoor temperature Ta is "-2.79", the quantized value will be "-3.0". Note that the quantization of numerical values ​​in the setting unit 52 is not limited to the method exemplified here, and other appropriate methods such as rounding off, rounding up, or rounding down may be used.

[0030] The setting unit 52 calculates the target pressure saturation temperature ST based on the set reference pressure saturation temperature ST1, for example, according to the following formula (1): Target pressure saturation temperature ST = reference pressure saturation temperature ST1 + set temperature correction value Th1 + eco level correction value Th2 + other correction values ​​Th3 (1)

[0031] In the above formula (1), the set temperature correction value Th1 corrects the target pressure saturation temperature ST based on the set temperature of each of the multiple indoor units 3 acquired by the acquisition unit 51 of the multiple indoor units 3. The setting unit 52 adjusts the target pressure saturation temperature ST based on the set temperature with the greatest degree of capacity requirement, among the set temperatures of each of the multiple indoor units 3 acquired by the acquisition unit 51. In other words, the indoor unit 3 with the largest difference between the outdoor temperature Ta and the set temperature Ts of the multiple indoor units 3 has the highest capacity requirement for the outdoor unit 2. The setting unit 52 identifies the set temperature Ts with the largest difference from the outdoor temperature Ta, among the set temperatures Ts of the multiple indoor units 3.

[0032] The setting unit 52 determines the set temperature correction value Th1, for example, using the following equation (2) and applies it to the above equation (1): Set temperature correction value Th1=Specified set temperature Ts-Constant K (2) Here, the constant K can be set, for example, to K=24. For example, if the lowest set temperature Ts of the multiple indoor units 3 is Ts=20°C, then based on the above equation (2), the set temperature correction value Th1=20-24=-4°C.

[0033] In the above formula (1), when one of the following energy saving levels is set in each of the multiple indoor units 3 as the energy saving level during operation: Lv1: Eco mode Low Lv2: Eco mode Medium Lv3: Eco mode High Lv4: Eco mode Super High, eco level correction Th2 is used to make a correction according to the set energy saving level.

[0034] Here, the setting unit 52 adjusts the target pressure saturation temperature ST based on the energy-saving level that places the greatest degree of capacity demand on the outdoor unit 2, among the energy-saving level settings (Lv1 to Lv4) for each of the multiple indoor units 3 acquired by the acquisition unit 51. Specifically, the energy-saving levels, Lv1 to Lv4, decrease in order of the capacity demand on the outdoor unit 2. For this reason, the setting unit 52 identifies the energy-saving level that places the greatest degree of capacity demand on the outdoor unit 2, among the energy-saving levels set for the multiple indoor units 3.

[0035] The setting unit 52 acquires a correction value for the eco level correction Th2 corresponding to the energy saving level with the highest degree of capacity requirement. For this reason, the energy saving level and the correction value for the eco level correction Th2 are stored in association with each other in the storage unit 54. For example, the following settings are made: Lv1: In the case of the low eco mode, the eco level correction Th2 = 15°C Lv2: In the medium eco mode, the eco level correction Th2 = 10°C Lv3: In the high eco mode, the eco level correction Th2 = 5°C Lv4: In the super high eco mode, the eco level correction Th2 = 0°C

[0036] In the above formula (1), the other correction value Th3 can be set based on, for example, the indoor humidity. For example, if the indoor humidity detected by the humidity sensor 32 remains higher than a preset humidity reference value for, say, three minutes, the other correction value Th3 as the flag count value is decremented by "1." If the initial value of the other correction value Th3 of the flag count value is Th3=0, when the humidity remains higher than the humidity reference value for three minutes, the other correction value Th3 of the flag count value is decremented by "1," resulting in Th3=-1. Thereafter, the other correction value Th3 of the flag count value is decremented by "1" each time the humidity remains higher than the humidity reference value for three minutes. As a result, as the duration of the humidity remaining higher than the humidity reference value increases, the other correction value Th3 fluctuates, such as -2, -3, ... This is because by increasing the amount of subtraction from the target pressure saturation temperature ST using the other correction value Th3, the target pressure saturation temperature ST is lowered, the output from the outdoor unit 2 is increased, and the dehumidification performance in the room is improved.

[0037] In this manner, the setting unit 52 sets the target pressure saturation temperature ST based on the above formula (1). The setting unit 52 checks whether the target pressure saturation temperature ST set using the above formula (1) is within a range between a preset lower limit value Tmin and an upper limit value Tmax of the target pressure saturation temperature. If the target pressure saturation temperature ST is less than the lower limit value Tmin, the setting unit 52 sets the target pressure saturation temperature ST to the lower limit value Tmin. Furthermore, if the target pressure saturation temperature ST exceeds the upper limit value Tmax, the setting unit 52 sets the target pressure saturation temperature ST to the upper limit value Tmax. The lower limit value of the target pressure saturation temperature ST is set to a predetermined constant value. Meanwhile, the upper limit value Tmax may be set to a predetermined constant value. Alternatively, for example, as shown in FIG. 5 , multiple upper limit values ​​Tmax1 to Tmax4 may be set according to the energy-saving levels Lv1 to Lv4.

[0038] The setting unit 52 outputs the target pressure saturation temperature ST set in this manner to the compressor control unit 53. The compressor control unit 53 operates the compressor 21 at a rotation speed according to the output target pressure saturation temperature.

[0039] (Procedure of the control method for the air conditioning system) As shown in FIG. 6, the outdoor unit control device 50 acquires information on the outdoor temperature detected by the outdoor temperature sensor 25 and the indoor humidity detected by the humidity sensor 32 of the indoor unit 3 (step S11).

[0040] Next, the setting unit 52 sets the target pressure saturation temperature ST (step S12). To do this, the setting unit 52 first references the correlation information D1 shown in FIG. 4 based on the outdoor temperature sensor 25 and acquires the reference pressure saturation temperature ST1 corresponding to the outdoor temperature Ta at that time. The setting unit 52 then calculates the target pressure saturation temperature ST based on the reference pressure saturation temperature ST1 and the above formula (1). To do this, the setting unit 52 acquires a set temperature correction value Th1 using the above formula (2) based on the set temperatures of the multiple indoor units 3 acquired by the acquisition unit 51 for the multiple indoor units 3. The setting unit 52 also acquires a correction value corresponding to the energy-saving level set for each of the multiple indoor units 3. The setting unit 52 also acquires an other correction value Th3 as a flag count value that is counted based on the indoor humidity detected by the humidity sensor 32.

[0041] After setting the target pressure saturation temperature ST based on the above formula (1), the set target pressure saturation temperature ST is output to the compressor control unit 53, and the compressor control unit 53 operates the compressor 21 at a rotation speed corresponding to the output target pressure saturation temperature (step S13).

[0042] Thereafter, the series of processes from steps S11 to S13 described above is repeated at predetermined time intervals, for example, every minute, to update the target pressure saturation temperature ST, and the compressor 21 continues to operate based on the updated target pressure saturation temperature ST.

[0043] (Effects) According to the air conditioning system 1, the control method for the air conditioning system 1, and the program configured as described above, by setting a target pressure saturation temperature based on a reference pressure saturation temperature corresponding to the outdoor temperature, the output of the compressor 21 of the outdoor unit 2 can be made to correspond to the outdoor temperature. This makes it possible to reduce the deviation of the output of the compressor 21 of the outdoor unit 2 from the capacity required by the indoor unit 3. This reduces the need for the heat exchanger 33 on the indoor unit 3 side to be repeatedly turned on and off intermittently. As a result, the operating efficiency of the air conditioning system 1 can be improved while more precisely adjusting the temperature in the indoor unit 3.

[0044] Furthermore, by adjusting the target pressure saturation temperature based on the set temperature of each of the multiple indoor units 3, it is possible to determine the required capacity of each indoor unit 3 from the set temperature of the indoor units 3. Therefore, the target pressure saturation temperature can be adjusted according to the required capacity of each indoor unit 3.

[0045] Furthermore, by adjusting the target pressure saturation temperature based on the set temperature of the plurality of indoor units 3 that has the greatest degree of capacity requirement, the output of the outdoor unit 2 can be adjusted without excess or deficiency.

[0046] Furthermore, by adjusting the target pressure saturation temperature based on the level of energy-saving operation, it is possible to reduce the deviation of the output of the compressor 21 of the outdoor unit 2 from the required capacity from the indoor unit 3 according to the level of energy-saving operation.

[0047] Although the above embodiment has been described with reference to a cooling operation, similar control can also be performed in a heating operation. To calculate the reference pressure saturation temperature, correlation information D2, which indicates the correlation between the outdoor temperature Ta and the reference pressure saturation temperature during heating operation, is used, as shown in FIG. 7 . In this case, for example, when the outdoor temperature is 12°C or higher, the reference pressure saturation temperature is set to T11. As the outdoor temperature drops below 12°C, the reference pressure saturation temperature is gradually increased. When the outdoor temperature is below −10°C, the reference pressure saturation temperature is set to T12, which is higher than T11. Furthermore, as shown in FIG. 8 , the upper limit value when the setting unit 52 sets the target pressure saturation temperature ST may be set to Tmax11 if the outdoor temperature Ta is −15°C or higher, gradually decreased if the outdoor temperature Ta is below −15°C, and set to Tmax12, which is lower than Tmax11, if the outdoor temperature Ta is below −25°C.

[0048] (Other Embodiments) While the embodiments of the present disclosure have been described above in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and design modifications and the like are also included within the scope of the present disclosure. Note that a program for implementing all or part of the functions of the indoor unit control device 40 and the outdoor unit control device 50 may be recorded on a computer-readable recording medium, and the program may be loaded into a computer system and executed to perform processing by each functional unit. The term "computer system" as used herein includes hardware such as an OS and peripheral devices. Furthermore, if a WWW system is used, the term "computer system" also includes a website provision environment (or display environment). Furthermore, the term "computer-readable recording medium" refers to portable media such as CDs, DVDs, and USBs, as well as storage devices such as hard disks built into the computer system. Furthermore, if the program is distributed to the indoor unit control device 40 and the outdoor unit control device 50 via a communication line, the indoor unit control device 40 and the outdoor unit control device 50 may then load the program into their storage and execute the above-described processing. Furthermore, the above program may be one that realizes part of the functions described above, or may be one that can realize the functions described above in combination with a program already recorded in the computer system.

[0049] <Additional Notes> The air conditioning system 1, the control method for the air conditioning system 1, and the program described in the embodiment can be understood, for example, as follows.

[0050] (1) An air conditioning system 1 according to a first aspect comprises an outdoor unit 2 equipped with a compressor 21 that compresses a heat medium; a plurality of indoor units 3 connected to the outdoor unit 2 via a medium circuit 5 through which the heat medium flows and equipped with a heat exchanger 33 that exchanges heat between the heat medium supplied from the compressor 21 via the medium circuit 5 and indoor air; an outdoor temperature sensor 25 that detects the temperature outside the room where the outdoor unit 2 is installed; an outdoor unit control device 50 that controls the operation of the outdoor unit 2; and an indoor unit control device 40 that is provided in each of the plurality of indoor units 3 and controls the operation of the indoor unit 3 in accordance with a set temperature that is set externally. The outdoor unit control device 50 includes a setting unit 52 that acquires, as a reference pressure saturation temperature, a pressure saturation temperature that corresponds to the outdoor temperature detected by the outdoor temperature sensor 25 based on predetermined correlation information that indicates a correlation between the outdoor temperature and a reference pressure saturation temperature, and sets the target pressure saturation temperature based on the acquired reference pressure saturation temperature.

[0051] In this air conditioning system 1, by setting a target pressure saturation temperature based on a reference pressure saturation temperature corresponding to the outdoor temperature, the output of the compressor 21 in the outdoor unit 2 can be made to correspond to the outdoor temperature. This makes it possible to reduce the deviation of the output of the compressor 21 in the outdoor unit 2 from the capacity required by the indoor unit 3. This reduces the need for the heat exchanger 33 in the indoor unit 3 to be intermittently turned on and off repeatedly. As a result, the operating efficiency of the air conditioning system 1 can be improved while more precisely adjusting the temperature in the indoor unit 3.

[0052] (2) The air conditioning system 1 according to the second aspect is the air conditioning system 1 of (1), further comprising an acquisition unit 51 that acquires the set temperature in the indoor unit 3, and the setting unit 52 adjusts the target pressure saturation temperature based on the set temperature in each of the plurality of indoor units 3 acquired by the acquisition unit 51.

[0053] This makes it possible to grasp the required capacity of each indoor unit 3 from the set temperature of the indoor unit 3 , and to adjust the target pressure saturation temperature according to the required capacity of each indoor unit 3 .

[0054] (3) The air conditioning system 1 according to the third aspect is the air conditioning system 1 according to (2), in which the setting unit 52 adjusts the target pressure saturation temperature based on the set temperature with the greatest degree of capacity requirement among the set temperatures for each of the plurality of indoor units 3 acquired by the acquisition unit 51.

[0055] As a result, by adjusting the target pressure saturation temperature based on the set temperature of the plurality of indoor units 3 that has the greatest degree of capacity requirement, the output of the outdoor unit 2 can be adjusted without excess or deficiency.

[0056] (4) The air conditioning system 1 according to a fourth aspect is any one of the air conditioning systems 1 of (1) to (3), in which the indoor unit control device 40 controls the operation of the indoor unit 3 in accordance with the level of energy-saving operation set externally, and the setting unit 52 adjusts the target pressure saturation temperature based on the level of energy-saving operation set in the indoor unit control device 40.

[0057] This allows the target pressure saturation temperature to be adjusted based on the level of energy-saving operation, thereby reducing the deviation of the output of the compressor 21 of the outdoor unit 2 from the required capacity from the indoor unit 3 according to the level of energy-saving operation.

[0058] (5) A fifth aspect of the control method for an air conditioning system 1 is a control method for an air conditioning system 1 including an outdoor unit 2 equipped with a compressor 21 and a plurality of indoor units 3, in which a pressure saturation temperature corresponding to a detected outdoor temperature is acquired as a reference pressure saturation temperature based on predetermined correlation information indicating the correlation between the outdoor temperature and a reference pressure saturation temperature, and the target pressure saturation temperature is set based on the acquired reference pressure saturation temperature.

[0059] This control method for the air conditioning system 1 sets a target pressure saturation temperature based on a reference pressure saturation temperature corresponding to the outdoor temperature, thereby making it possible to make the output of the compressor 21 of the outdoor unit 2 correspond to the outdoor temperature. This makes it possible to reduce the deviation of the output of the compressor 21 of the outdoor unit 2 from the capacity required by the indoor unit 3. This reduces the need for the heat exchanger 33 on the indoor unit 3 side to be intermittently turned on and off repeatedly. As a result, it is possible to improve the operating efficiency of the air conditioning system 1 while more precisely adjusting the temperature in the indoor unit 3.

[0060] (6) A program according to a sixth aspect causes a computer of an air conditioning system 1 including an outdoor unit 2 with a compressor 21 and a plurality of indoor units 3 to execute a process of acquiring a pressure saturation temperature corresponding to a detected outdoor temperature as a reference pressure saturation temperature based on predetermined correlation information indicating the correlation between the outdoor temperature and a reference pressure saturation temperature, and setting the target pressure saturation temperature based on the acquired reference pressure saturation temperature.

[0061] This program sets the target pressure saturation temperature based on the reference pressure saturation temperature corresponding to the outdoor temperature, thereby making it possible to make the output of the compressor 21 of the outdoor unit 2 correspond to the outdoor temperature. This makes it possible to reduce the deviation of the output of the compressor 21 of the outdoor unit 2 from the capacity required by the indoor unit 3. This reduces the need for the heat exchanger 33 on the indoor unit 3 side to be intermittently turned on and off repeatedly. As a result, it is possible to improve the operating efficiency of the air conditioning system 1 while more precisely adjusting the temperature in the indoor unit 3.

[0062] According to each embodiment of the present disclosure, it is possible to improve the operating efficiency while performing more detailed temperature adjustment in the indoor unit.

[0063] DESCRIPTION OF SYMBOLS 1...Air conditioning system 2...Outdoor unit 3...Indoor unit 5...Connecting pipe (medium circuit) 21...Compressor 23...Outdoor unit 25...Outdoor temperature sensor 27...Pressure sensor 27a...Suction side sensor 27b...Discharge side sensor 31...Indoor temperature sensor 32...Humidity sensor 33...Heat exchanger 38...Remote controller 40...Indoor unit control device 41...Information acquisition unit 42...External input acceptance unit 43...Operation control unit 46...Output unit 50...Outdoor unit control device 51...Acquisition unit 52...Setting unit 53...Compressor control unit 54...Storage unit D1...Correlation information D2...Correlation information

Claims

1. An air conditioning system comprising: an outdoor unit equipped with a compressor that compresses a heat medium; a plurality of indoor units connected to the outdoor unit via a medium circuit through which a heat medium flows, and equipped with a heat exchanger that exchanges heat between the heat medium supplied from the compressor via the medium circuit and indoor air; an outdoor temperature sensor that detects the outdoor temperature where the outdoor unit is installed; an outdoor unit control device that controls the operation of the outdoor unit; and an indoor unit control device that is provided in each of the plurality of indoor units and controls the operation of the indoor unit in accordance with a set temperature that is set externally, wherein the outdoor unit control device includes a setting unit that acquires, as a reference pressure saturation temperature, a pressure saturation temperature corresponding to the outdoor temperature detected by the outdoor temperature sensor based on predetermined correlation information indicating a correlation between the outdoor temperature and a reference pressure saturation temperature, and sets a target pressure saturation temperature for adjusting an output of the compressor based on the acquired reference pressure saturation temperature.

2. The air conditioning system of claim 1, further comprising an acquisition unit that acquires a set temperature in the indoor unit, wherein the setting unit adjusts the target pressure saturation temperature based on the set temperature in each of the plurality of indoor units acquired by the acquisition unit.

3. The air conditioning system of claim 2, wherein the setting unit adjusts the target pressure saturation temperature based on the set temperature having the greatest degree of capacity requirement among the set temperatures for each of the multiple indoor units acquired by the acquisition unit.

4. An air conditioning system as described in claim 1 or 2, wherein the indoor unit control device controls the operation of the indoor unit according to an energy-saving operation level set externally, and the setting unit adjusts the target pressure saturation temperature based on the energy-saving operation level set in the indoor unit control device.

5. A control method for an air conditioning system having an outdoor unit and a plurality of indoor units, comprising: acquiring a pressure saturation temperature corresponding to a detected outdoor temperature as a reference pressure saturation temperature based on predetermined correlation information indicating a correlation between the outdoor temperature and a reference pressure saturation temperature; and setting a target pressure saturation temperature for adjusting compressor output based on the acquired reference pressure saturation temperature.

6. A program for causing a computer of an air conditioning system equipped with an outdoor unit and a plurality of indoor units to execute a process of acquiring a pressure saturation temperature corresponding to a detected outdoor temperature as a reference pressure saturation temperature based on predetermined correlation information indicating a correlation between the outdoor temperature and a reference pressure saturation temperature, and setting a target pressure saturation temperature for adjusting the output of a compressor based on the acquired reference pressure saturation temperature.

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