Air conditioning equipment and air conditioning systems

Abstract

An air-conditioning device (1) comprises: a detection device that detects data during the operation of each refrigerant circuit (10A, 10B); and a control device (20). The control device (20) computes, from the data detected by the detection device, an air-conditioning processing performance demonstrated by the air-conditioning device (1), controls each of compressors (2) so as to operate in a first mode when the ratio of the computed air-conditioning processing performance to the rated performance of the air-conditioning device (1) is greater than a preset threshold, and controls each of the compressors (2) so as to operate in a second mode when said ratio is less than or equal to the threshold. The control device (20) performs control using a first threshold as the threshold when the number of air-conditioning systems in operation is less than a specific number from among a plurality of air-conditioning systems, and performs control using a second threshold, which is greater than the first threshold, as the threshold when the number of air-conditioning systems in operation is the specific number or greater.

Description

Technical Field

[0001] The present disclosure relates to an air conditioner and an air conditioning system.

Background Art

[0002] Conventionally, there is known an air conditioner that performs control (hereinafter also referred to as energy-saving control) to improve the operating efficiency by changing the target evaporation temperature for evaporating the refrigerant in the evaporator according to the air conditioning load. In an air conditioner that performs energy-saving control, in a building with a small air conditioning load or in an intermediate period (spring and autumn) with a small generated heat load, since the temperature of the refrigerant can be controlled to the target evaporation temperature by a slight temperature change, a greater energy-saving effect is expected. In such an air conditioner, mainly from the viewpoint of ensuring comfort, the indoor temperature is brought close to the set temperature set by the user in a short time, so the specification is such that energy-saving control is not entered for a certain period of time from the start (thermo-on) of the compressor.

[0003] The air conditioner of Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2002-147823) determines the control characteristics of the target value of the evaporation temperature corresponding to the cooling load characteristics of the building. The air conditioner of Patent Document 1 is configured to change the target value of the evaporation temperature based on the internal and external temperature difference between the set temperature inside the room and the outside air temperature according to this control characteristic.

[0004] The air conditioner of Patent Document 2 (Japanese Unexamined Patent Application Publication No. 2015-021656) predicts the generated heat load from the difference temperature between the set temperature inside the room and the actual suction temperature, performs thermo-on, and continues the operation for a certain period of time. Thereafter, when the difference temperature is greater than the set value, the air conditioner of Patent Document 2 performs control to set the rotation speed of the compressor to the minimum value.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0006] When selecting air conditioning systems, there is a tendency to choose systems with a capacity that is slightly excessive for the air conditioning load. As a result, even in the summer when the air conditioning load is high, for example, air conditioning systems with a capacity that is slightly excessive for the air conditioning load have a low load ratio relative to the air conditioning capacity (hereinafter also referred to as the air conditioning load ratio). When attempting to implement energy-saving control using air conditioning systems with a low air conditioning load ratio, the challenge is that the expected energy-saving effect cannot be achieved because the compressor is repeatedly started (thermo-on) and stopped (thermo-off).

[0007] The air conditioning system described in Patent Document 1 (Japanese Patent Publication No. 2002-147823) can suppress excessive air conditioning capacity when an indoor-outdoor temperature difference, which is the difference between the set indoor temperature and the outdoor temperature, is always present. However, the air conditioning system described in Patent Document 1 (Japanese Patent Publication No. 2002-147823) does not take into consideration reducing the frequency of starting and stopping the compressor when the air conditioning load factor is low.

[0008] The air conditioning system described in Patent Document 2 (Japanese Patent Publication No. 2015-021656) can predict the generated heat load from the temperature difference between the set temperature and the intake temperature, thereby reducing the frequency of starting and stopping the compressor. However, the air conditioning system described in Patent Document 2 (Japanese Patent Publication No. 2015-021656) does not take into account cases where the air conditioning load rate is low and a temperature difference between the set temperature and the intake temperature is unlikely to occur, and in such cases, the energy-saving effect is limited.

[0009] The air conditioning systems described in Patent Document 1 (Japanese Unexamined Patent Publication No. 2002-147823) and Patent Document 2 (Japanese Unexamined Patent Publication No. 2015-021656) have only one air conditioning system that air-conditions the target space, and therefore do not consider air conditioning systems that air-condition a target space using multiple air conditioning systems.

[0010] The purpose of this disclosure is to provide an air conditioning device and air conditioning system that can achieve energy-saving effects when using an air conditioning device with a low air conditioning load factor, and that can be operated considering the air conditioning of a target space by multiple air conditioning systems. [Means for solving the problem]

[0011] The air conditioning system described herein relates to an air conditioning system that air-conditions a target space using multiple air conditioning systems. Each of the multiple air conditioning systems has a refrigerant circuit consisting of a first heat exchanger located outside the target space, a second heat exchanger located inside the target space, an expansion valve, and a compressor. In the refrigerant circuit of each air conditioning system, refrigerant flows in the order of compressor, first heat exchanger, expansion valve, second heat exchanger, and compressor during cooling operation. The air conditioning system includes a detection device that detects data during the operation of each refrigerant circuit and a control device that controls each refrigerant circuit. The control device calculates the air conditioning processing capacity exhibited by the air conditioning system from the data detected by the detection device, and controls each compressor to operate in first mode if the ratio of the calculated air conditioning processing capacity to the rated capacity of the air conditioning system is greater than a preset threshold, and controls each compressor to operate in second mode if the ratio is less than or equal to the threshold. The first mode is an operating mode in which, after a certain grace period has elapsed since the start of operation of each compressor, the control system changes the target temperature of the refrigerant flowing through the corresponding second heat exchanger from the first temperature to a second temperature that is different from the first temperature. The second mode is an operating mode in which, after a shorter grace period than in the first mode since the start of operation of each compressor, the control system changes the target temperature of the refrigerant flowing through the corresponding second heat exchanger from the first temperature to a second temperature. The control device performs control using the first threshold as the threshold when fewer than a certain number of air conditioning systems are in operation, and performs control using the second threshold, which is greater than the first threshold, when a certain number or more of air conditioning systems are in operation.

[0012] The air conditioning system according to this disclosure comprises an air conditioning device that air-conditions a target space using multiple air conditioning systems, and a server device connected to the air conditioning device via a network. Each of the multiple air conditioning systems has a refrigerant circuit consisting of a first heat exchanger located outside the target space, a second heat exchanger located inside the target space, an expansion valve, and a compressor. In the refrigerant circuit of each air conditioning system, refrigerant flows in the order of compressor, first heat exchanger, expansion valve, second heat exchanger, and compressor during cooling operation. The air conditioning device comprises a detection device that detects data during the operation of each refrigerant circuit, and a control device that controls each refrigerant circuit. The server device calculates the air conditioning processing capacity exerted by the air conditioning device from the data detected by the detection device, and if the ratio of the calculated air conditioning processing capacity to the rated capacity of the air conditioning device is greater than a preset threshold, it creates first control data to operate each compressor in first mode, and if the ratio is less than or equal to the threshold, it creates second control data to operate each compressor in second mode. The first control data is control data that changes the target temperature of the refrigerant flowing through the corresponding second heat exchanger from the first temperature to a second temperature different from the first temperature after a certain grace period has elapsed since the start of operation of each compressor. The second control data is control data that changes the target temperature of the refrigerant flowing through the corresponding second heat exchanger from the first temperature to the second temperature after a shorter grace period than the first mode has elapsed since the start of operation of each compressor. The server device creates control data using the first threshold as the threshold when fewer than a certain number of air conditioning systems are in operation, and creates control data using the second threshold, which is greater than the first threshold, as the threshold when more than a certain number of air conditioning systems are in operation. [Effects of the Invention]

[0013] According to the air conditioning device and air conditioning system of this disclosure, the air conditioning processing capacity performed by the air conditioning device is calculated from the data detected by the detection device, and if the ratio of the calculated air conditioning processing capacity to the rated capacity of the air conditioning device is greater than a preset threshold, each compressor is controlled to operate in the first mode, and if the ratio is less than or equal to the threshold, each compressor is controlled to operate in the second mode. The control device performs control using the first threshold as the threshold when fewer than a specified number of air conditioning systems are in operation among multiple air conditioning systems, and performs control using the second threshold, which is greater than the first threshold, as the threshold when a specified number or more of air conditioning systems are in operation. As a result, the air conditioning device and air conditioning system of this disclosure can achieve energy saving effects when using an air conditioning device with a low air conditioning load factor, and can also be operated considering that the target space is air-conditioned by multiple air conditioning systems. [Brief explanation of the drawing]

[0014] [Figure 1] This is a schematic diagram showing the configuration of the air conditioning system in Embodiment 1. [Figure 2] This diagram shows the refrigerant circuit of the air conditioning system in Embodiment 1. [Figure 3] This diagram shows the arrangement of indoor units within the target space in Embodiment 1. [Figure 4] This graph shows the relationship between the difference between the intake temperature and the set temperature in the indoor unit, and the target evaporation temperature. [Figure 5] This graph shows the relationship between time and the target evaporation temperature. [Figure 6] This is a flowchart showing the control during cooling operation in Embodiment 1. [Figure 7] This diagram shows the arrangement of indoor units within the target space in Embodiment 2. [Figure 8] This is a flowchart showing the control during cooling operation in Embodiment 2. [Figure 9] This diagram shows the arrangement of indoor units within the target space in Embodiment 3. [Figure 10]It is a flowchart showing control during the cooling operation in Embodiment 3. [Figure 11] It is a schematic diagram showing the configuration of the air conditioning system in Embodiment 4.

Modes for Carrying Out the Invention

[0015] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the embodiments described below, when referring to the number, amount, etc., unless otherwise specified, the scope of the present disclosure is not necessarily limited to the number, amount, etc. The same parts and corresponding parts are given the same reference numerals, and duplicate explanations may not be repeated. It is initially planned to use the configurations in the embodiments in appropriate combinations.

[0016] Embodiment 1. FIG. 1 is a schematic diagram showing the configuration of the air conditioner 1 in Embodiment 1. The air conditioner 1 includes an indoor unit 110A, an outdoor unit 12 connected to the indoor unit 110A, an indoor unit 110B, an outdoor unit 12 connected to the indoor unit 110B, and a control device 20. Each of the indoor units 110A and 110B includes a plurality of indoor machines 11. The number of indoor machines 11 included in one indoor unit may be any number. The air conditioner 1 may be configured to include three or more indoor units.

[0017] In the air conditioner 1, a plurality of indoor machines 11 and an outdoor unit 12 are connected by pipes to form a refrigerant circuit. The inside of the pipes is configured such that refrigerant circulates. The outdoor unit 12 is installed outside the target space to be air-conditioned. The indoor machine 11 is installed inside the target space to be air-conditioned. The air conditioner 1 air-conditions the target space by a plurality of air-conditioning (refrigerant) systems. The target space is, for example, the interior of a building. Hereinafter, the refrigerant circuit composed of a plurality of indoor machines 11 and an outdoor unit 12 will be described as one air-conditioning (refrigerant) system.

[0018] The refrigerant used to fill the refrigerant circuit may be, for example, an HFC refrigerant such as R32, an HCFC refrigerant such as R22, or a natural refrigerant such as R410A, CO2, or R290. Other refrigerants may also be used.

[0019] The control device 20 consists of a CPU (Central Processing Unit) 21, memory 22 (ROM (Read Only Memory) and RAM (Random Access Memory)), and input / output devices (not shown) for inputting and outputting various signals. The CPU 21 loads the program stored in ROM into RAM and executes it. The program stored in ROM is a program that describes the processing procedure of the control device 20. The control device 20 controls each device in the indoor unit 11 and the outdoor unit 12 according to these programs. This control is not limited to software processing; it can also be processed by dedicated hardware (electronic circuits). The control device 20 can be installed on either the indoor unit 11 side or the outdoor unit 12 side.

[0020] Figure 2 shows the refrigerant circuit of the air conditioning system 1 in Embodiment 1. The air conditioning system 1 comprises a refrigerant circuit 10A and a refrigerant circuit 10B. The refrigerant circuit 10A comprises a plurality of indoor units 11 included in the indoor unit 110A and an outdoor unit 12. The refrigerant circuit 10B comprises a plurality of indoor units 11 included in the indoor unit 110B and an outdoor unit 12. The outdoor unit 12 includes a compressor 2, a four-way valve 3, an outdoor heat exchanger 4, and a fan 7. The indoor unit 11 includes an expansion valve 5, an indoor heat exchanger 6, and a fan 8.

[0021] Compressor 2 draws in refrigerant, compresses it, and discharges it. The four-way valve 3 switches the direction of refrigerant circulation between cooling and heating operation. In refrigerant circuits 10A and 10B in Figure 2, the direction of refrigerant flow during cooling operation is indicated by solid arrows. During cooling operation, the indoor heat exchanger 6 functions as an evaporator, and the outdoor heat exchanger 4 functions as a condenser. During heating operation, the direction of refrigerant flow is reversed. During heating operation, the indoor heat exchanger 6 functions as a condenser, and the outdoor heat exchanger 4 functions as an evaporator.

[0022] The outdoor heat exchanger 4 has multiple heat transfer tubes and performs heat exchange between outdoor air blown by the fan 7 and refrigerant passing through the multiple heat transfer tubes. The expansion valve 5 expands and depressurizes the refrigerant. The expansion valve 5 is a device that can arbitrarily control the opening degree, such as an electronic expansion valve. The indoor heat exchanger 6 has multiple heat transfer tubes and performs heat exchange between indoor air blown by the fan 8 and refrigerant passing through the multiple heat transfer tubes.

[0023] The air conditioning system 1 is equipped with multiple sensors as detection devices to detect data during operation of refrigerant circuits 10A and 10B. A pressure sensor 31a is provided on the refrigerant suction side of the compressor 2 to detect the low pressure of refrigerant circuits 10A and 10B. A pressure sensor 31b is provided on the refrigerant discharge side of the compressor 2 to detect the high pressure of refrigerant circuits 10A and 10B. Refrigerant temperature sensors 32a and 32b are provided at both ends of the outdoor heat exchanger 4 to detect the temperature of the refrigerant. When the outdoor heat exchanger 4 functions as a condenser, refrigerant temperature sensor 32a detects the refrigerant temperature on the inlet side of the outdoor heat exchanger 4, and refrigerant temperature sensor 32b detects the refrigerant temperature on the outlet side of the outdoor heat exchanger 4. When the outdoor heat exchanger 4 functions as an evaporator, refrigerant temperature sensor 32a detects the refrigerant temperature on the outlet side of the outdoor heat exchanger 4, and refrigerant temperature sensor 32b detects the refrigerant temperature on the inlet side of the outdoor heat exchanger 4.

[0024] Refrigerant temperature sensors 33a and 33b are provided at both ends of the indoor heat exchanger 6 to detect the temperature of the refrigerant. When the indoor heat exchanger 6 functions as an evaporator, refrigerant temperature sensor 33b detects the refrigerant temperature on the inlet side of the indoor heat exchanger 6, and refrigerant temperature sensor 33a detects the refrigerant temperature on the outlet side of the indoor heat exchanger 6. When the indoor heat exchanger 6 functions as a condenser, refrigerant temperature sensor 33b detects the refrigerant temperature on the outlet side of the indoor heat exchanger 6, and refrigerant temperature sensor 33a detects the refrigerant temperature on the inlet side of the indoor heat exchanger 6. Refrigerant temperature sensors 32a, 32b, 33a, and 33b are connected to the control device 20 via signal lines (not shown). Pressure sensors 31a and 31b are connected to the control device 20 via signal lines (not shown).

[0025] Although not shown in the diagram, the outdoor unit 12 is equipped with an outdoor temperature sensor for detecting the outside air temperature, and the indoor unit 11 is equipped with a room temperature sensor for detecting the indoor temperature and a humidity sensor for detecting the indoor humidity. The indoor unit 11 may also be equipped with an airflow sensor for detecting the airflow rate at the air outlet. These sensors should be connected to the control device 20 via signal lines (not shown). As a result, the data detected by each sensor is transmitted to the control device 20.

[0026] The control device 20 performs calculations using the data transmitted from each sensor. Details of the calculations will be described later. The control device 20 controls the compressor 2, fans 7 and 8, and expansion valve 5 using the control data created based on the calculations.

[0027] Figure 3 shows the arrangement of indoor units in the target space in Embodiment 1. As shown in Figure 3, the target space TS includes an air conditioning (refrigerant) system 200A and an air conditioning (refrigerant) system 200B. Multiple indoor units 11 are arranged in air conditioning (refrigerant) systems 200A and 200B. The number and arrangement of indoor units 11 may be arranged in any way, and the number of air conditioning (refrigerant) systems may be increased.

[0028] Next, we will explain the relationship between the difference between the intake temperature and the set temperature in indoor units 110A and 110B during cooling operation, and the target evaporation temperature. Figure 4 is a graph showing the relationship between the difference between the intake temperature and the set temperature in indoor units 110A and 110B, and the target evaporation temperature. The intake temperature is the room temperature detected by the indoor temperature sensor installed in the indoor unit 11. The set temperature is any temperature set by the user via an input device such as a remote control. The target evaporation temperature is the target temperature of the refrigerant flowing through the indoor heat exchanger 6, which functions as an evaporator.

[0029] As shown in Figure 4, when the difference between the intake temperature and the set temperature in indoor units 110A and 110B is small, the target evaporation temperature is high. Conversely, when the difference between the intake temperature and the set temperature in indoor units 110A and 110B is large, the target evaporation temperature is low. In other words, when the difference between the intake temperature and the set temperature is small, the target evaporation temperature can be set higher than when the difference is large. Being able to set a higher target evaporation temperature means that the change in the operating frequency of compressor 2 can be controlled more gradually. Therefore, when the target evaporation temperature is set high, a greater energy saving effect can be obtained than when the target evaporation temperature is set low.

[0030] Figure 5 is a graph showing the relationship between time and target evaporation temperature. Figure 5(a) shows the relationship between time and target evaporation temperature when the compressor 2 is controlled in the first mode during normal operation. Figure 5(b) shows the relationship between time and target evaporation temperature when the compressor 2 is controlled in the second mode during energy-saving operation. In the figures, "thermo-on" indicates that the compressor 2 is started, and "thermo-off" indicates that the compressor 2 is stopped. The control device 20 performs control in either the first or second mode by controlling the rotational speed of the compressor 2. Note that "thermo-on" also means controlling the rotational speed to increase it from zero to a predetermined value when the compressor 2 is started, so it can also be said to be an operation to set the rotational speed.

[0031] As shown in Figure 5(a), in the first mode, after the thermostat is turned on, the control device 20 maintains the temperature of the refrigerant in the indoor heat exchanger 6, which functions as an evaporator, at the target value a[°C] for a predetermined grace period β1[min]. After the grace period β1[min] has elapsed, the control device 20 controls the system to change the target value of the refrigerant temperature from a[°C] to b[°C], which is higher than a[°C]. β1 is, for example, 10[min]. The temperature of the refrigerant in the indoor heat exchanger 6 is changed from a[°C] to b[°C]. After maintaining the target value of the refrigerant temperature at b[°C] for a certain period of time, the control device 20 turns off the compressor 2. Thereafter, the control device 20 repeatedly turns the compressor 2's thermostat on and off by repeatedly controlling the system to change the target evaporation temperature from a[°C] to b[°C].

[0032] As shown in Figure 5(b), in the second mode, after the thermostat is turned on, the control device 20 controls the temperature of the refrigerant in the indoor heat exchanger 6 to change from the target value a[°C] to b[°C], which is higher than a[°C], without providing a grace period β1[min]. As a result, the temperature of the refrigerant in the indoor heat exchanger 6 is changed from a[°C] to b[°C]. After maintaining the target value of the refrigerant temperature at b[°C] for a certain period of time, the control device 20 turns the compressor 2 off with the thermostat. In the second mode, there is no grace period β1[min], and the period during which the target value of the refrigerant temperature is b[°C] is longer than in the first mode. In other words, in the second mode, the period during which the target value of the refrigerant temperature is controlled to b[°C] is longer than in the first mode, and the number of times the compressor 2 is turned on and off with the thermostat is reduced accordingly.

[0033] In Figure 5, a[°C] is, for example, 0[°C], and b[°C] is, for example, 9[°C]. As shown in Figure 4, setting a higher target evaporation temperature results in greater energy savings than setting a lower target evaporation temperature. Therefore, the second mode, in which the period during which the target refrigerant temperature is b[°C] is longer than that of the first mode, can be said to have a higher energy-saving effect.

[0034] Here, we will explain in detail the first mode of normal operation and the second mode of energy-saving operation. In the first mode, the refrigerant temperature is set low immediately after the compressor 2 thermostat turns on, allowing the room temperature to approach the user-set temperature in a short time. In other words, the first mode is an operation that extends the time spent rapidly cooling at a low temperature, and then gradually changes to the set temperature. For this reason, the first mode can reduce discomfort and improve comfort in a short time.

[0035] In the second mode, energy-saving effects are achieved when using an air conditioning system 1 with a low air conditioning load factor. A low air conditioning load factor means that the indoor temperature can be effectively lowered even with less power consumption. By using an air conditioning system 1 with a low air conditioning load factor, it becomes possible to gradually process the indoor heat load at a high target evaporation temperature, and the period during which the temperature is controlled at a high target evaporation temperature can be extended. In other words, the second mode eliminates the initial period of rapid cooling and operates in a way that cools the indoor temperature over a long period until it reaches the set temperature. As a result, in the second mode, the number of times the compressor 2 is turned on and off can be reduced compared to the first mode, and a high energy-saving effect can be obtained when using an air conditioning system 1 with a low air conditioning load factor.

[0036] Next, we will describe the control actions performed by the control device 20. Figure 6 is a flowchart showing the control during cooling operation in Embodiment 1. The processes in the flowchart in Figure 6 are repeatedly called and executed as subroutines from the main routine in the control of the control device 20. Figure 6 will explain the processes during cooling operation.

[0037] In step S (hereinafter simply referred to as "S") 11, the control device 20 first acquires operating data during cooling operation from multiple sensors, which are detection devices. Next, the control device 20 calculates the air conditioning processing capacity (the generated air conditioning load) (S12). Here, the air conditioning processing capacity is the processing capacity of the air conditioning unit 1. Therefore, the air conditioning processing capacity is equal in magnitude to the generated air conditioning load in that the air conditioning load generated in the room changes when the processing capacity is exerted. The calculation of the air conditioning processing capacity is determined, for example, by the method described in Japanese Patent No. 6739671. Specifically, the control device 20 determines the refrigerant flow rate in the outdoor unit 12 from a data table showing the relationship between the rotational speed of the compressor 2, the high pressure detected from the pressure sensor 31b, the low pressure detected from the pressure sensor 31a, and the refrigerant flow rate.

[0038] The control device 20 determines the Cv value from the opening degree of the expansion valve 5 and the expansion valve characteristic data table. The Cv value is a unique coefficient that indicates the ease of fluid flow. The control device 20 uses the Cv value to determine the refrigerant flow rate in the indoor unit 11. Specifically, the control device 20 determines this using the following relationship: refrigerant flow rate of the target indoor unit 11 = refrigerant flow rate of the outdoor unit 12 × [Cv value of the target indoor unit 11 / sum of Cv values ​​of the indoor unit 11]. Next, the control device 20 determines the evaporator inlet specific enthalpy using the liquid refrigerant temperature at the refrigerant outlet of the outdoor unit 12 and the specific enthalpy data table for the evaporator inlet. The control device 20 determines the evaporator outlet specific enthalpy using the liquid refrigerant temperature and gaseous refrigerant temperature of the indoor unit 11 and the evaporator outlet specific enthalpy data table. The control device 20 calculates the air conditioning capacity [kW] = refrigerant flow rate of indoor unit 11 [kg / h] / 3600 × [equal enthalpy at evaporator outlet - specific enthalpy at evaporator inlet] [kJ / kg]. The control device 20 adds up the air conditioning capacity of each indoor unit 11 to determine the total air conditioning capacity of indoor unit 110A. The control device 20 similarly calculates the air conditioning capacity of indoor unit 110B and adds them up to determine the air conditioning capacity of the air conditioning system 1.

[0039] Next, the control device 20 calculates the ratio of the air conditioning processing capacity to the rated capacity of the air conditioning unit 1 = [air conditioning processing capacity (air conditioning load) / rated capacity] (S13). Next, the control device 20 determines whether or not there are multiple air conditioning (refrigerant) systems in operation in the target space TS (S14). The control device 20 determines whether or not there are multiple air conditioning (refrigerant) systems in operation in the target space TS by receiving data, for example, that the user has entered, indicating which air conditioning (refrigerant) system to operate.

[0040] In S14, the control device 20 determines whether the air conditioning processing capacity (air conditioning load) / rated capacity ≤ α1 (NO in S14) if it determines that there are no multiple air conditioning (refrigerant) systems operating in the target space TS (only one air conditioning (refrigerant) system is operating). α1 is an arbitrary setting value that can be set by the user to determine whether or not to use energy-saving control during cooling operation. In S15, the control device 20 determines that the air conditioning processing capacity (air conditioning load) / rated capacity > α1 (NO in S15), and sets the compressor 2 to be controlled in the first mode, which is normal operation (S17), and returns the processing from the subroutine to the main routine. The first mode is a mode in which a grace period β1 is set.

[0041] In S15, if the control device 20 determines that the air conditioning processing capacity (air conditioning load) / rated capacity ≤ α1 (YES in S15), it sets the control device 2 to control the compressor 2 in the second mode, which is energy-saving operation (S16), and returns the processing from the subroutine to the main routine. The second mode is a mode in which the refrigerant temperature is changed without a grace period β1.

[0042] In S14, if the control device 20 determines that there are multiple air conditioning (refrigerant) systems in operation in the target space TS (two air conditioning (refrigerant) systems are in operation) (YES in S14), it determines whether the air conditioning processing capacity (air conditioning load) / rated capacity ≤ α2 (S18). α2 is an arbitrary setting value that can be set by the user to determine whether or not to use energy-saving control during cooling operation. In S18, if the control device 20 determines that the air conditioning processing capacity (air conditioning load) / rated capacity > α2 (NO in S18), it sets the compressor 2 to be controlled in the first mode, which is normal operation (S20), and returns the processing from the subroutine to the main routine. The first mode is a mode in which a grace period β1 is set.

[0043] In S18, if the control device 20 determines that the air conditioning processing capacity (air conditioning load) / rated capacity ≤ α2 (YES in S18), it sets the control device 2 to control the compressor 2 in the second mode, which is energy-saving operation (S19), and returns the processing from the subroutine to the main routine. The second mode is a mode in which the refrigerant temperature is changed without a grace period β1.

[0044] In the second mode, the number of thermo-on and thermo-off cycles of the compressor 2 in the air conditioning system 1 is approximately halved compared to the first mode. This allows the air conditioning system 1 to spend more time at the target evaporation temperature (for example, b [°C] in Figure 5), enabling energy-saving operation. Furthermore, the determination value for the ratio of the air conditioning processing capacity in the air conditioning system 1 is set to α1 < α2. For example, α1 is 0.7 and α2 is 0.8.

[0045] Here, a large value of α indicates that there is surplus capacity in the air conditioning system. In other words, when there are multiple air conditioning (refrigerant) systems in operation in the target space TS, the threshold criteria can be relaxed compared to when there are no multiple air conditioning (refrigerant) systems in operation in the target space TS, so the value of α is set to be larger. As a result, when there are multiple air conditioning (refrigerant) systems in operation in the target space TS, the air conditioning system 1 can more easily enter energy-saving operation than when there are no multiple air conditioning (refrigerant) systems in operation in the target space TS.

[0046] Thus, the air conditioning system 1 can achieve energy-saving effects when using an air conditioning system 1 with a low air conditioning load factor, and it can also be operated considering that the target space TS is air-conditioned by multiple air conditioning (refrigerant) systems.

[0047] During heating operation, by switching the four-way valve 3 shown in Figure 2 to the dotted line side, the indoor heat exchanger 6 functions as a condenser and the outdoor heat exchanger 4 functions as an evaporator. During heating operation, the target condensation temperature (the target temperature of the refrigerant flowing through the indoor heat exchanger 6, which functions as a condenser) shown in Figure 5 is used instead of the target evaporation temperature. For example, referring to Figure 5, in the first mode, after the thermostat is turned on, the control device 20 maintains the temperature of the refrigerant in the indoor heat exchanger 6, which functions as a condenser, at the target value a [°C] for a predetermined grace period β2 [min]. After the grace period β2 [min] has elapsed, the control device 20 controls the target value of the refrigerant temperature to change from a [°C] to b [°C], which is lower than a [°C]. The temperature of the refrigerant in the indoor heat exchanger 6 is changed from a [°C] to b [°C]. After maintaining the target value of the refrigerant temperature at b [°C] for a certain period of time, the control device 20 turns off the compressor 2 with the thermostat. Subsequently, the control device 20 repeatedly switches the compressor 2's thermostat on and off by repeatedly changing the target condensation temperature from a[°C] to b[°C].

[0048] In the second mode, after the thermostat is turned on, the control device 20 controls the temperature of the refrigerant in the indoor heat exchanger 6 to change from the target value a1[°C] to b1[°C], which is lower than a1[°C], without providing a grace period β2[min]. As a result, the temperature of the refrigerant in the indoor heat exchanger 6 is changed from a1[°C] to b1[°C]. After maintaining the target value of the refrigerant temperature at b1[°C] for a certain period of time, the control device 20 turns the compressor 2 off with the thermostat. In the second mode, there is no grace period β2[min], and the period during which the target value of the refrigerant temperature is b1[°C] is longer than in the first mode. In other words, in the second mode, the period during which the target value of the refrigerant temperature is controlled at b1[°C] is longer than in the first mode, and the number of times the compressor 2 is turned on and off with the thermostat is reduced accordingly. As a result, the air conditioning system 1 can spend more time at the target condensation temperature, enabling energy-saving operation.

[0049] Thus, the temperature relationship during heating operation is reversed compared to cooling operation. The control device 20 executes the processes corresponding to S11 to S20 during heating operation in the same way as during cooling operation.

[0050] Embodiment 2. The air conditioning system 1 of Embodiment 2 differs from Embodiment 1 in that the target space TS is divided into an interior zone IZ and a perimeter zone PZ. Below, we will mainly explain the parts that differ from Embodiment 1, and will omit explanations of the same configuration as Embodiment 1. Figure 7 is a diagram showing the arrangement of indoor units 11 in the target space TS in Embodiment 2. Here, the interior zone is the central part of a room in a building, etc., where the effect of air conditioning is great and the temperature is not easily affected by sunlight, outside air, etc. The perimeter zone is an area near windows, etc., where the outside air has an effect and the air conditioning load is large.

[0051] As shown in Figure 7, the area corresponding to the first region near the boundary between the target space TS and the area outside the target space TS is the perimeter zone PZ. As shown in Figure 7, the area corresponding to the second region inside the perimeter zone PZ is the interior zone IZ. As shown in Figure 7, the interior zone IZ consists of air conditioning (refrigerant) systems 201A and 201B. As shown in Figure 7, the perimeter zone PZ consists of air conditioning (refrigerant) systems 201C and 201D. Note that the number of air conditioning (refrigerant) systems included in each zone may be one or three or more.

[0052] Next, we will describe the control actions performed by the control device 20. Figure 8 is a flowchart showing the control during cooling operation in Embodiment 2. The processes in the flowchart in Figure 8 are repeatedly called and executed as subroutines from the main routine in the control of the control device 20. Figure 8 will explain the processes during cooling operation.

[0053] First, in step S31, the control device 20 acquires operating data during cooling operation from multiple sensors, which are detection devices. Next, the control device 20 calculates the air conditioning processing capacity (the generated air conditioning load) (S32). Next, the control device 20 determines the ratio of the air conditioning processing capacity to the rated capacity of the air conditioning system 1 = [air conditioning processing capacity (air conditioning load) / rated capacity] (S33). Next, the control device 20 determines whether or not there are multiple air conditioning (refrigerant) systems in operation in the target space TS (S34). The control device 20 determines whether or not there are multiple air conditioning (refrigerant) systems in operation by receiving, for example, data entered by the user indicating which air conditioning (refrigerant) system to operate.

[0054] In S34, the control device 20 determines whether the air conditioning processing capacity (air conditioning load) / rated capacity ≤ α1 (NO in S34) if it determines that there are no multiple air conditioning (refrigerant) systems operating in the target space TS (only one air conditioning (refrigerant) system is operating). α1 is an arbitrary setting value that can be set by the user to determine whether or not to use energy-saving control during cooling operation. In S35, the control device 20 determines that the air conditioning processing capacity (air conditioning load) / rated capacity > α1 (NO in S35), and sets the compressor 2 to be controlled in the first mode, which is normal operation (S37), and returns the processing from the subroutine to the main routine. The first mode is a mode in which a grace period β1 is set.

[0055] In S35, if the control device 20 determines that the air conditioning processing capacity (air conditioning load) / rated capacity ≤ α1 (YES in S35), it sets the control device 2 to control the compressor 2 in the second mode, which is energy-saving operation (S36), and returns the processing from the subroutine to the main routine. The second mode is a mode in which the refrigerant temperature is changed without a grace period β1. Here, the processing in S36 assumes that the interior zone IZ is in operation, and excludes the case where only the perimeter zone PZ is in operation. This is because when only the perimeter zone PZ is in operation, the air conditioning load is high, so the system does not transition to energy-saving operation.

[0056] In S34, if the control device 20 determines that there are multiple air conditioning (refrigerant) systems operating in the target space TS (two air conditioning (refrigerant) systems are operating in the interior zone IZ) (YES in S34), it determines whether or not the air conditioning includes the perimeter zone PZ (S38). The control device 20 determines whether or not the air conditioning (refrigerant) system in the perimeter zone PZ is operating by receiving data, for example, that has been input by the user indicating whether or not to operate the air conditioning (refrigerant) system in the perimeter zone PZ. In S38, if the control device 20 determines that the air conditioning includes the perimeter zone PZ (YES in S38), it determines whether or not the air conditioning processing capacity (air conditioning load) / rated capacity ≤ α3 (S39). α3 is an arbitrary setting value set by the user to determine whether or not to use energy-saving control during cooling operation.

[0057] If the control device 20 determines in S39 that the air conditioning processing capacity (air conditioning load) / rated capacity > α3 (NO in S39), it sets the control device 2 to control the compressor 2 in the first mode, which is normal operation (S41), and returns the processing from the subroutine to the main routine. If the control device 20 determines in S39 that the air conditioning processing capacity (air conditioning load) / rated capacity ≤ α3 (YES in S39), it sets the control device 20 to control the compressor 2 in the second mode, which is energy-saving operation (S40), and returns the processing from the subroutine to the main routine.

[0058] If the control device 20 determines in S38 that the air conditioning does not include the perimeter zone PZ (NO in S38), it determines whether the air conditioning processing capacity (air conditioning load) / rated capacity ≤ α2 (S42). α2 is an arbitrary setting value that can be set by the user to determine whether or not to use energy-saving control during cooling operation.

[0059] If the control device 20 determines in S42 that the air conditioning processing capacity (air conditioning load) / rated capacity > α2 (NO in S42), it sets the compressor 2 to be controlled in the first mode, which is normal operation (S44), and returns the processing from the subroutine to the main routine. If the control device 20 determines in S42 that the air conditioning processing capacity (air conditioning load) / rated capacity ≤ α2 (YES in S42), it sets the compressor 2 to be controlled in the second mode, which is energy-saving operation (S43), and returns the processing from the subroutine to the main routine.

[0060] In the air conditioning system 1 of Embodiment 2, the determination value for the ratio of air conditioning processing capacity is set to α3 < α1 < α2. For example, α1 is 0.7, α2 is 0.9, and α3 is 0.6. Here, a large value of α means that there is ample capacity for air conditioning. On the other hand, a small value of α means that there is no ample capacity for air conditioning and that the temperature needs to be changed quickly. In the process shown in Figure 8, if there are no multiple air conditioning (refrigerant) systems operating in the target space TS (when one air conditioning (refrigerant) system is operating in the interior zone IZ), the control device 20 switches between the first mode and the second mode of control using α1 as a moderate threshold. Also, in the process shown in Figure 8, if there are multiple air conditioning (refrigerant) systems operating in the target space TS (when two air conditioning (refrigerant) systems are operating in the interior zone IZ), the control device 20 determines whether or not the air conditioning (refrigerant) system in the perimeter zone PZ is operating.

[0061] In the process shown in Figure 8, when the air conditioning (refrigerant) system in the perimeter zone PZ is in operation, the control device 20 strengthens the threshold to enable rapid temperature changes and switches between the first mode and the second mode, using α3, which is lower than α1, as the threshold. On the other hand, when the air conditioning (refrigerant) system in the perimeter zone PZ is not in operation, the control device 20 relaxes the threshold and switches between the first mode and the second mode, using α2, which is higher than α1, as the threshold.

[0062] Thus, the air conditioning system 1 can achieve energy-saving effects when used with a low air conditioning load factor, and can also be operated considering that the target space TS is air-conditioned by multiple air conditioning (refrigerant) systems. Furthermore, since the air conditioning system 1 switches between the first mode and the second mode of control using different thresholds depending on whether the air conditioning (refrigerant) system in the perimeter zone PZ is in operation or not, it is possible to operate the system while considering the air conditioning (refrigerant) system in the perimeter zone PZ.

[0063] During heating operation, by switching the four-way valve 3 shown in Figure 2 to the dotted line side, the indoor heat exchanger 6 functions as a condenser and the outdoor heat exchanger 4 functions as an evaporator. During heating operation, the temperature relationship is reversed compared to cooling operation, as described above. The control device 20 performs the processes corresponding to S31 to S44 during heating operation in the same way as during cooling operation.

[0064] Embodiment 3. The air conditioning system 1 of Embodiment 3 differs from Embodiment 1 in that it has a walled-off area within the target space TS. Below, we will focus on the differences from Embodiment 1, and omit the explanation of the configuration which is the same as Embodiment 1. Figure 9 is a diagram showing the arrangement of the indoor unit 11 within the target space TS in Embodiment 3. The target space TS in Embodiment 3 has three walled-off areas KS. Each area KS has an independent air conditioning (refrigerant) system as a third air conditioning (refrigerant) system. Area KS is envisioned as, for example, a room such as a conference room in a building.

[0065] As shown in Figure 9, a fourth air conditioning (refrigerant) system, consisting of air conditioning (refrigerant) system 202A and air conditioning (refrigerant) system 202B, is installed in the area within the target space TS that is not enclosed by walls. Although the area where air conditioning (refrigerant) systems 202A and 202B are installed can actually be considered enclosed by walls when viewed from the perspective of the building as a whole, it will be described below as an area enclosed by walls. Area KS may be provided with only one air conditioning (refrigerant) system, and the number of air conditioning (refrigerant) systems can be changed as appropriate.

[0066] Next, we will describe the control actions performed by the control device 20. Figure 10 is a flowchart showing the control during cooling operation in Embodiment 3. The processes in the flowchart of Figure 10 are repeatedly called and executed as subroutines from the main routine in the control of the control device 20. Figure 10 will explain the processes during cooling operation.

[0067] In step S51, the control device 20 first acquires operating data during cooling operation from multiple sensors, which are detection devices. Next, the control device 20 calculates the air conditioning processing capacity (the generated air conditioning load) (S52). Next, the control device 20 determines the ratio of the air conditioning processing capacity to the rated capacity of the air conditioning system 1 = [air conditioning processing capacity (air conditioning load) / rated capacity] (S53). Next, the control device 20 determines whether there are multiple air conditioning (refrigerant) systems in operation in the target space TS (S54). The control device 20 determines whether there are multiple air conditioning (refrigerant) systems in operation by receiving data, for example, that the user has entered, indicating which air conditioning (refrigerant) system to operate.

[0068] In S54, the control device 20 determines whether the air conditioning processing capacity (air conditioning load) / rated capacity ≤ α1 if it determines that there are no multiple air conditioning (refrigerant) systems operating in the target space TS (only one air conditioning (refrigerant) system is operating) (NO in S54). α1 is an arbitrary setting value that can be set by the user to determine whether or not to use energy-saving control during cooling operation. In S55, the control device 20 determines that the air conditioning processing capacity (air conditioning load) / rated capacity > α1 (NO in S55), and sets the compressor 2 to be controlled in the first mode, which is normal operation (S57), and returns the processing from the subroutine to the main routine. The first mode is a mode in which a grace period β1 is set.

[0069] In S55, if the control device 20 determines that the air conditioning processing capacity (air conditioning load) / rated capacity ≤ α1 (YES in S55), it sets the control device 2 to control the compressor 2 in the second mode, which is energy-saving operation (S56), and returns the processing from the subroutine to the main routine. The second mode is a mode in which the refrigerant temperature is changed without a grace period β1. Here, the processing in S54 assumes that the fourth air conditioning (refrigerant) system in the area not enclosed by walls is in operation, and excludes the case where only the third air conditioning (refrigerant) system located in area KS is in operation.

[0070] In S54, if the control device 20 determines that there are multiple operating air conditioning (refrigerant) systems in the target space TS (two air conditioning (refrigerant) systems are operating in an area not enclosed by walls) (YES in S54), it determines whether the air conditioning system includes an area KS enclosed by walls, such as a conference room (S58). The control device 20 determines whether the air conditioning (refrigerant) system in area KS is operating, for example, by receiving data entered by the user indicating whether the air conditioning (refrigerant) system in area KS is operating. In S58, if the control device 20 determines that the air conditioning system includes an area KS enclosed by walls, such as a conference room (YES in S58), it determines whether the air conditioning processing capacity (air conditioning load) / rated capacity ≤ α3 (S59). α3 is an arbitrary setting value set by the user to determine whether or not to use energy-saving control during cooling operation.

[0071] If the control device 20 determines in S59 that the air conditioning processing capacity (air conditioning load) / rated capacity > α3 (NO in S59), it sets the control device 2 to control the compressor 2 in the first mode, which is normal operation (S61), and returns the processing from the subroutine to the main routine. If the control device 20 determines in S59 that the air conditioning processing capacity (air conditioning load) / rated capacity ≤ α3 (YES in S59), it sets the control device 20 to control the compressor 2 in the second mode, which is energy-saving operation (S60), and returns the processing from the subroutine to the main routine.

[0072] In S58, if the control device 20 determines that the air conditioning does not include a walled-off area KS such as a conference room (NO in S58), it determines whether the air conditioning processing capacity (air conditioning load) / rated capacity ≤ α2 (S62). α2 is an arbitrary setting value that can be set by the user to determine whether or not to use energy-saving control during cooling operation.

[0073] If the control device 20 determines in S62 that the air conditioning processing capacity (air conditioning load) / rated capacity > α2 (NO in S62), it sets the compressor 2 to be controlled in the first mode, which is normal operation (S64), and returns the processing from the subroutine to the main routine. If the control device 20 determines in S62 that the air conditioning processing capacity (air conditioning load) / rated capacity ≤ α2 (YES in S62), it sets the compressor 2 to be controlled in the second mode, which is energy-saving operation (S63), and returns the processing from the subroutine to the main routine.

[0074] In the third embodiment, the determination value for the ratio of air conditioning processing capacity in the air conditioning device 1 is set to α3 < α1 < α2. For example, α1 is 0.7, α2 is 0.8, and α3 is 0.6. Here, a large value of α means that there is ample capacity for air conditioning. On the other hand, a small value of α means that there is no capacity for air conditioning and it is necessary to change the temperature quickly. In the process shown in Figure 10, if there are no multiple operating air conditioning (refrigerant) systems in the target space TS (i.e., one air conditioning (refrigerant) system is operating in an area not enclosed by walls), the control device 20 switches between the first mode and the second mode of control using α1 as a moderate threshold. Also, in the process shown in Figure 10, if there are multiple operating air conditioning (refrigerant) systems in the target space TS (i.e., two air conditioning (refrigerant) systems are operating in an area not enclosed by walls), the control device 20 determines whether or not the air conditioning (refrigerant) system in an area KS enclosed by walls, such as a conference room, is operating.

[0075] In the process shown in Figure 10, if the air conditioning (refrigerant) system of a walled-off area KS, such as a conference room, is in operation, the control device 20 strengthens the threshold to enable rapid temperature changes and switches between the first mode and the second mode, using α3, which is lower than α1, as the threshold. On the other hand, if the air conditioning (refrigerant) system of a walled-off area KS, such as a conference room, is not in operation, the control device 20 relaxes the threshold and switches between the first mode and the second mode, using α2, which is higher than α1, as the threshold.

[0076] Thus, the air conditioning system 1 can achieve energy-saving effects when used with a low air conditioning load factor, and can also be operated considering that the target space TS is air-conditioned by multiple air conditioning (refrigerant) systems. Furthermore, the air conditioning system 1 switches between the first mode and the second mode of control using different thresholds depending on whether the air conditioning (refrigerant) system of a walled-off area KS, such as a conference room, is in operation or not, thus enabling operation that takes into account the air conditioning (refrigerant) system of a walled-off area KS, such as a conference room.

[0077] During heating operation, by switching the four-way valve 3 shown in Figure 2 to the dotted line side, the indoor heat exchanger 6 functions as a condenser and the outdoor heat exchanger 4 functions as an evaporator. During heating operation, the temperature relationship is reversed compared to cooling operation, as described above. The control device 20 performs the processes corresponding to S51 to S64 during heating operation in the same way as during cooling operation.

[0078] Embodiment 4. The air conditioning system 100 of Embodiment 4 differs in that the air conditioning device 1 is connected to the server device 40 via a network 9. Figure 11 is a schematic diagram showing the configuration of the air conditioning system 100 in Embodiment 4. As shown in Figure 11, the server device 40 is composed of a CPU (Central Processing Unit) 41, memory 42 (ROM (Read Only Memory) and RAM (Random Access Memory)), and input / output devices (not shown) for inputting and outputting various signals. The CPU 41 loads the program stored in ROM into RAM and executes it. The program stored in ROM is a program that describes the processing procedure of the server device 40. This control is not limited to software processing, but can also be processed by dedicated hardware (electronic circuits).

[0079] In the air conditioning system 100, some of the processing performed by the control device 20 of the air conditioning unit 1 is performed by the server device 40. The processing performed by the control device 20 and the server device 40 of the air conditioning unit 1 is described below. The control device 20 transmits detection data of the operation of the refrigerant circuits 10A and 10B, detected by multiple sensors, to the server device 40. The server device 40 calculates the air conditioning processing capacity performed by the air conditioning unit 1 based on the received detection data, using the processing flow shown in Figure 6. The server device 40 receives data from the user indicating which air conditioning (refrigerant) system to operate, and determines whether there are multiple air conditioning (refrigerant) systems operating in the target space TS.

[0080] The server device 40 determines whether the ratio of the air conditioning processing capacity (air conditioning load) / rated capacity, calculated using different thresholds depending on whether there are multiple air conditioning (refrigerant) systems operating in the target space TS, to the rated capacity of the air conditioning unit 1 is below the threshold. If the ratio is greater than a preset threshold, the server device 40 creates control data to operate each compressor 2 in the first mode, and if the ratio is below the threshold, it creates control data to operate each compressor 2 in the second mode.

[0081] The server device 40 transmits the created control data to the control device 20. Based on the received control data, the control device 20 controls the compressor 2 to operate in either the first mode or the second mode. This reduces the processing load on the control device 20.

[0082] <Variation> In the air conditioning system 1, the case in which the control device 20 controls the rotational speed of the compressor 2 to perform control in either the first or second mode has been described. The control device 20 may also control the rotational speed of the fan 8 in addition to controlling the compressor 2. During cooling operation, the control device 20 may perform control to change the target temperature of the refrigerant flowing through the indoor heat exchanger 6 from the first temperature to a second temperature higher than the first temperature by reducing the rotational speed of the fan 8. During heating operation, the control device 20 may perform control to change the target temperature of the refrigerant flowing through the indoor heat exchanger 6 from the first temperature to a second temperature lower than the first temperature by reducing the rotational speed of the fan 8. The air conditioning system 1 may further perform control to change the target temperature using the fan 7 of the outdoor unit 12. The air conditioning system 1 may also perform control in either the first or second mode by controlling only the fans 7 and 8.

[0083] The air conditioning device 1 and air conditioning system 100 have been described in a case where no grace period is provided in the second mode. However, the air conditioning device 1 and air conditioning system 100 may also be configured to provide a shorter grace period in the second mode than in the first mode.

[0084] <Summary> This disclosure relates to an air conditioning system 1 that air-conditions a target space TS using multiple air conditioning systems. Each of the multiple air conditioning systems has a refrigerant circuit 10A, 10B consisting of an outdoor heat exchanger 4 located outside the target space TS, an indoor heat exchanger 6 located inside the target space TS, an expansion valve 5, and a compressor 2. In the refrigerant circuits 10A, 10B of each air conditioning system, the refrigerant flows in the order of compressor 2, outdoor heat exchanger 4, expansion valve 5, indoor heat exchanger 6, and compressor 2 during cooling operation. The air conditioning system 1 includes a plurality of sensors as detection devices for detecting data during operation of each refrigerant circuit 10A, 10B, and a control device 20 for controlling each refrigerant circuit 10A, 10B. The control device 20 calculates the air conditioning capacity performed by the air conditioning system 1 from the data detected by the detection device. If the ratio of the calculated air conditioning capacity to the rated capacity of the air conditioning system 1 is greater than a preset threshold, the control device 2 controls each compressor 2 to operate in the first mode. If the ratio is less than or equal to the threshold, the control device 2 controls each compressor 2 to operate in the second mode. The first mode is an operating mode in which, after a certain grace period has elapsed since the start of operation of each compressor 2, the control device changes the target temperature of the refrigerant flowing through the corresponding indoor heat exchanger 6 from the first temperature to a second temperature different from the first temperature. The second mode is an operating mode in which, after a shorter grace period than in the first mode since the start of operation of each compressor 2, the control device changes the target temperature of the refrigerant flowing through the corresponding indoor heat exchanger 6 from the first temperature to the second temperature. The control device 20 performs control using a first threshold when fewer than a specified number of air conditioning systems are in operation, and performs control using a second threshold that is greater than the first threshold when a specified number or more of air conditioning systems are in operation.

[0085] Preferably, the multiple air conditioning systems include a first air conditioning system in which a region corresponding to a first region near the boundary between the target space TS and the outside of the target space TS is located in the perimeter zone PZ, and a second air conditioning system located in the interior zone IZ corresponding to a second region inside the first region (perimeter zone PZ). When the control device 20 determines that the refrigerant circuits of the first air conditioning system and the second air conditioning system are operating, it executes control using a third threshold less than or equal to the first threshold, and when it determines that only the refrigerant circuit of the second air conditioning system is operating, it executes control using a second threshold.

[0086] Preferably, the multiple air conditioning systems include a third air conditioning system included in a walled-off region KS within the target space TS, and a fourth air conditioning system not included in the walled-off region KS within the target space TS. When the control device 20 determines that the refrigerant circuits of the third air conditioning system and the fourth air conditioning system are operating, it executes control using a third threshold less than or equal to the first threshold, and when it determines that only the refrigerant circuit of the fourth air conditioning system is operating, it executes control using a second threshold.

[0087] Preferably, the second temperature is higher than the first temperature. Each indoor heat exchanger 6 functions as an evaporator during cooling operation. During cooling operation in the second mode, the control device 20 performs control to change the target temperature of the refrigerant flowing through each indoor heat exchanger 6 from the first temperature to the second temperature.

[0088] Preferably, each of the multiple air conditioning systems further includes a fan 8 that supplies air to exchange heat with the refrigerant flowing through the indoor heat exchanger 6. The control device 20 performs control to change the target value of the refrigerant temperature from a first temperature to a second temperature by reducing the rotational speed of each fan 8.

[0089] Preferably, the second temperature is lower than the first temperature. Each indoor heat exchanger 6 functions as a condenser during heating operation. During heating operation in the second mode, the control device 20 performs control to change the target temperature of the refrigerant flowing through each indoor heat exchanger 6 from the first temperature to the second temperature.

[0090] Preferably, each of the multiple air conditioning systems further includes a fan 8 that supplies air to exchange heat with the refrigerant flowing through the indoor heat exchanger 6. The control device 20 performs control to change the target value of the refrigerant temperature from a first temperature to a second temperature by reducing the rotational speed of each fan 8.

[0091] The air conditioning system 100 of this disclosure includes an air conditioning device 1 that air-conditions a target space TS using multiple air conditioning systems, and a server device 40 connected to the air conditioning device 1 via a network 9. Each of the multiple air conditioning systems has a refrigerant circuit 10A, 10B consisting of an outdoor heat exchanger 4 located outside the target space TS, an indoor heat exchanger 6 located inside the target space TS, an expansion valve 5, and a compressor 2. In the refrigerant circuits 10A, 10B of each air conditioning system, the refrigerant flows in the order of compressor 2, outdoor heat exchanger 4, expansion valve 5, indoor heat exchanger 6, and compressor 2 during cooling operation. The air conditioning device 1 includes a plurality of sensors as detection devices for detecting data during operation of each refrigerant circuit 10A, 10B, and a control device 20 for controlling each refrigerant circuit 10A, 10B. The server device 40 calculates the air conditioning capacity performed by the air conditioning system 1 from the data detected by the detection device. If the ratio of the calculated air conditioning capacity to the rated capacity of the air conditioning system 1 is greater than a preset threshold, it creates first control data to operate each compressor 2 in first mode. If the ratio is less than or equal to the threshold, it creates second control data to operate each compressor 2 in second mode. The first control data is control data that changes the target temperature of the refrigerant flowing through the corresponding indoor heat exchanger 6 from first temperature to second temperature, which is different from first temperature, after a certain grace period has elapsed since the start of operation of each compressor 2. The second control data is control data that changes the target temperature of the refrigerant flowing through the corresponding indoor heat exchanger 6 from first temperature to second temperature after a shorter grace period than that for first mode since the start of operation of each compressor 2. The server device 40 creates control data using a first threshold when fewer than a specified number of air conditioning systems are in operation, and creates control data using a second threshold that is greater than the first threshold when more than a specified number of air conditioning systems are in operation.

[0092] Thus, with the air conditioning device 1 and air conditioning system 100 of this disclosure, it is possible to obtain energy-saving effects when using the air conditioning device 1 with a low air conditioning load factor, and it is also possible to operate the system while considering that the target space TS is air-conditioned by multiple air conditioning systems.

[0093] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of this disclosure is indicated by the claims rather than by the description of the embodiments above, and all modifications within the meaning and scope of the claims are intended to be included. [Explanation of symbols]

[0094] 1 Air conditioning unit, 2 Compressor, 3 Four-way valve, 4 Outdoor heat exchanger, 5 Expansion valve, 6 Indoor heat exchanger, 7,8 Fan, 9 Network, 10A,10B Refrigerant circuit, 11 Indoor unit, 12 Outdoor unit, 20 Control device, 31a,31b Pressure sensor, 32a,32b,33a,33b Refrigerant temperature sensor, 40 Server unit, 100 Air conditioning system, 110A,110B Indoor unit, 200A,200B,201A,201B,201C,201D,202A,202B Air conditioning (refrigerant) system, IZ Interior zone, KS Area, PZ Perimeter zone, TS Target space.

Claims

1. An air conditioning system that provides air conditioning for a target space using multiple air conditioning systems, Each of the aforementioned air conditioning systems has a refrigerant circuit comprising a first heat exchanger located outside the target space, a second heat exchanger located inside the target space, an expansion valve, and a compressor. In the refrigerant circuit of each air conditioning system, during cooling operation, the refrigerant flows in the following order: compressor, first heat exchanger, expansion valve, second heat exchanger, and compressor. The aforementioned air conditioning system, A detection device that detects data during the operation of each refrigerant circuit, It comprises a control device that controls each refrigerant circuit, The control device calculates the air conditioning capacity being performed by the air conditioning system from the data detected by the detection device, and controls each compressor to operate in the first mode if the ratio of the calculated air conditioning capacity to the rated capacity of the air conditioning system is greater than a preset threshold, and controls each compressor to operate in the second mode if the ratio is less than or equal to the threshold. The first mode is an operating mode that controls the change of the target temperature of the refrigerant flowing through the corresponding second heat exchanger from a first temperature to a second temperature different from the first temperature, after a certain grace period has elapsed since the start of operation of each compressor. The second mode is an operating mode that controls the change of the target temperature of the refrigerant flowing through the corresponding second heat exchanger from the first temperature to the second temperature, after a shorter grace period than in the first mode following the start of operation of each compressor. The control device, when fewer than a specified number of the air conditioning systems among the plurality of air conditioning systems are in operation, executes control using a first threshold as the threshold, and when the specified number or more of air conditioning systems are in operation, executes control using a second threshold that is greater than the first threshold as the threshold. An air conditioning system in which, when the second heat exchanger functions as an evaporator during cooling operation, the second temperature is set higher than the first temperature, and when the second heat exchanger functions as a condenser during heating operation, the second temperature is set lower than the first temperature.

2. The plurality of air conditioning systems include a first air conditioning system located in a first region within the target space that is close to the boundary between the target space and the area outside the target space, and a second air conditioning system located in a second region inside the first region. The control device is If it is determined that the refrigerant circuits of the first air conditioning system and the second air conditioning system are operating, control is performed using a third threshold less than or equal to the first threshold. The air conditioning device according to claim 1, which, when it is determined that only the refrigerant circuit of the second air conditioning system is operating, performs control using the second threshold.

3. The aforementioned plurality of air conditioning systems include a third air conditioning system included in a region enclosed by walls within the target space, and a fourth air conditioning system not included in a region enclosed by walls within the target space. The control device is If it is determined that the refrigerant circuits of the third air conditioning system and the fourth air conditioning system are operating, control is performed using the third threshold less than or equal to the first threshold. The air conditioning device according to claim 1, which, when it is determined that only the refrigerant circuit of the fourth air conditioning system is operating, performs control using the second threshold.

4. The air conditioning system according to any one of claims 1 to 3, wherein the control device performs control to change the target temperature of the refrigerant flowing through each second heat exchanger from the first temperature to the second temperature during cooling operation in the second mode.

5. Each of the aforementioned plurality of air conditioning systems further comprises a fan that supplies air that exchanges heat with the refrigerant flowing through the second heat exchanger, The air conditioning apparatus according to claim 4, wherein the control device performs control to change the target value of the refrigerant temperature from the first temperature to the second temperature by reducing the rotation speed of each fan.

6. The air conditioning system according to any one of claims 1 to 3, wherein the control device performs control to change the target temperature of the refrigerant flowing through each second heat exchanger from the first temperature to the second temperature during heating operation in the second mode.

7. Each of the aforementioned plurality of air conditioning systems further comprises a fan that supplies air that exchanges heat with the refrigerant flowing through the second heat exchanger, The air conditioning apparatus according to claim 6, wherein the control device performs control to change the target value of the refrigerant temperature from the first temperature to the second temperature by reducing the rotation speed of each fan.

8. An air conditioning system that provides air conditioning to a target space using multiple air conditioning systems, The system comprises a server device connected to the air conditioning system via a network, Each of the aforementioned air conditioning systems has a refrigerant circuit comprising a first heat exchanger located outside the target space, a second heat exchanger located inside the target space, an expansion valve, and a compressor. In the refrigerant circuit of each air conditioning system, during cooling operation, the refrigerant flows in the following order: compressor, first heat exchanger, expansion valve, second heat exchanger, and compressor. The aforementioned air conditioning system, A detection device that detects data during the operation of each refrigerant circuit, It comprises a control device that controls each refrigerant circuit, The server device calculates the air conditioning processing capacity performed by the air conditioning system from the data detected by the detection device, and if the ratio of the calculated air conditioning processing capacity to the rated capacity of the air conditioning system is greater than a preset threshold, it creates first control data to operate each compressor in first mode, and if the ratio is less than or equal to the threshold, it creates second control data to operate each compressor in second mode. The first control data is control data that changes the target temperature of the refrigerant flowing through the corresponding second heat exchanger from a first temperature to a second temperature different from the first temperature after a certain grace period has elapsed since the start of operation of each compressor. The second control data is control data that changes the target temperature of the refrigerant flowing through the corresponding second heat exchanger from the first temperature to the second temperature after a shorter grace period than the first mode from the start of operation of each compressor. The server device creates control data using a first threshold as the threshold when fewer than a specified number of the multiple air conditioning systems are in operation, and creates control data using a second threshold that is greater than the first threshold as the threshold when the specified number or more of the air conditioning systems are in operation. An air conditioning system in which, when the second heat exchanger functions as an evaporator during cooling operation, the second temperature is set higher than the first temperature, and when the second heat exchanger functions as a condenser during heating operation, the second temperature is set lower than the first temperature.

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