Outdoor unit and air conditioner

Abstract

One embodiment of an outdoor unit according to the present disclosure provides an outdoor unit of an air conditioner to which a plurality of indoor units are connected. The outdoor unit comprises: a plurality of refrigerant circuit units to each of which at least one indoor unit is connected; and a plurality of compressors respectively provided to the plurality of refrigerant circuit units. The amount of refrigerant sealed in the plurality of refrigerant circuit units is different from each other.

Description

Outdoor units and air conditioners

[0001] The present disclosure relates to an outdoor unit and an air conditioner.

[0002] For example, as disclosed in Patent Document 1, an outdoor unit (outdoor unit) including a plurality of refrigerant circuits (refrigerant circuit portions) is known.

[0003] Japanese Patent Application Laid-Open No. 2020-153593

[0004] In the outdoor unit described above, a compressor is provided for each of the multiple refrigerant circuits. When the compressors in the multiple refrigerant circuits are driven simultaneously, the compressors may resonate with each other, which may cause abnormal noise from the outdoor unit.

[0005] In view of the above circumstances, one object of the present disclosure is to provide an outdoor unit that can suppress the generation of abnormal noise, and an air conditioner that includes such an outdoor unit.

[0006] One aspect of the outdoor unit according to the present disclosure is an outdoor unit for an air conditioner, and is an outdoor unit to which a plurality of indoor units are connected, and is equipped with a plurality of refrigerant circuit sections to which at least one of the indoor units is each connected, and a plurality of compressors respectively provided in the plurality of refrigerant circuit sections, and the amounts of refrigerant sealed in the plurality of refrigerant circuit sections are different from one another.

[0007] One aspect of the outdoor unit according to the present disclosure is an outdoor unit for an air conditioner, and an outdoor unit to which a plurality of indoor units are connected, comprising a plurality of refrigerant circuit sections to which at least one of the indoor units is each connected, a plurality of compressors provided in each of the plurality of refrigerant circuit sections, and a control device that controls the plurality of refrigerant circuit sections, wherein the control device has a plurality of outdoor unit control sections provided for each of the plurality of refrigerant circuit sections, and the plurality of outdoor unit control sections are capable of independently controlling each of the plurality of refrigerant circuit sections, and each of the outdoor unit control sections is capable of controlling each of the refrigerant circuit sections based on information regarding the other refrigerant circuit sections obtained from the other outdoor unit control sections.

[0008] One aspect of the air conditioner according to the present disclosure includes the outdoor unit described above, and the plurality of indoor units connected to the outdoor unit.

[0009] According to the present disclosure, abnormal noise can be suppressed from being generated from the outdoor unit of an air conditioner.

[0010] 1 is a schematic diagram showing a general configuration of an air conditioner according to Embodiment 1. FIG. 2 is a perspective view showing a part of an outdoor unit according to Embodiment 1. FIG. 3 is a plan view showing a part of an outdoor unit according to Embodiment 1. FIG. 4 is a block diagram showing a part of the functional configuration of an air conditioner according to Embodiment 1. FIG. 5 is a graph showing an example of changes in the operating frequency of each compressor controlled by an outdoor unit control unit according to Embodiment 1. FIG. 6 is a schematic diagram showing a general configuration of an air conditioner according to Embodiment 2. FIG. 7 is a block diagram showing a part of the functional configuration of an air conditioner according to Embodiment 2. FIG. 8 is a flowchart showing an example of a control procedure performed by a first outdoor unit control unit according to Embodiment 2 before driving a first compressor. FIG. 9 is a flowchart showing an example of a control procedure when a first outdoor unit control unit according to Embodiment 2 adjusts the operating frequency of the first compressor. FIG. 10 is a diagram showing an example of changes in the operating frequency of each compressor and an example of changes in the temperature in each room according to Embodiment 2. FIG. 11 is a schematic diagram showing a general configuration of an air conditioner according to Embodiment 3.

[0011] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the scope of the present disclosure is not limited to the following embodiments and can be modified as desired within the scope of the technical concept of the present disclosure. In addition, in the following drawings, the scale and number of each structure may differ from the scale and number of the actual structure in order to make each configuration easier to understand.

[0012] Embodiment 1 Fig. 1 is a schematic diagram showing the general configuration of an air conditioner 100 in Embodiment 1. Fig. 2 is a perspective view showing a part of an outdoor unit 10 in Embodiment 1. Fig. 3 is a plan view showing a part of an outdoor unit 10 in Embodiment 1. Fig. 4 is a block diagram showing a part of the functional configuration of the air conditioner 100 in Embodiment 1.

[0013] 2 and 3 show the X-axis, Y-axis, and Z-axis. The X-axis indicates one of the horizontal directions. The Y-axis indicates the other of the horizontal directions. The Z-axis indicates the vertical direction. In the following description, the horizontal direction along the X-axis is referred to as the "front-rear direction X," the horizontal direction along the Y-axis is referred to as the "left-right direction Y," and the vertical direction along the Z-axis is referred to as the "vertical direction Z." The front-rear direction X, left-right direction Y, and vertical direction Z are perpendicular to each other. In the following description, the side of the vertical direction Z toward which the Z-axis arrow points (+Z side) is referred to as the upper side, and the side of the vertical direction Z opposite to the side toward which the Z-axis arrow points (-Z side) is referred to as the lower side. Furthermore, the side of the front-rear direction X toward which the X-axis arrow points (+X side) is referred to as the front side, and the side of the front-rear direction X opposite to the side toward which the X-axis arrow points (-X side) is referred to as the rear side. The left-right direction Y is the left-right direction when the outdoor unit 10 is viewed from the front (+X side). In other words, the side of the left-right direction Y toward which the Y-axis arrow points (+Y side) is the right side, and the side of the left-right direction Y opposite to the side toward which the Y-axis arrow points (-Y side) is the left side.

[0014] As shown in Fig. 1, the air conditioner 100 is a multi-type air conditioner that includes an outdoor unit 10 and a plurality of indoor units 20 connected to the outdoor unit 10. The outdoor unit 10 is located outdoors. The plurality of indoor units 20 are located indoors. Each indoor unit 20 is connected to the same outdoor unit 10 by a pair of refrigerant pipes 88a, 88b extending from each indoor unit 20.

[0015] In the first embodiment, four indoor units 20 are provided: two first indoor units 20a and two second indoor units 20b. The two first indoor units 20a and the two second indoor units 20b are arranged in different rooms. The two first indoor units 20a are arranged in the first room R1. The two second indoor units 20b are arranged in the second room R2.

[0016] The air conditioner 100 includes multiple circulating refrigerant circuits 110. The circulating refrigerant circuits 110 are refrigerant circuits in which a refrigerant 19 circulates through the outdoor unit 10 and at least one indoor unit 20. Examples of the refrigerant 19 include fluorine-based refrigerants or hydrocarbon-based refrigerants with low global warming potential (GWP). Examples of the refrigerant 19 include a single refrigerant selected from R1234yf, R1234ze, R32, and R290, a mixed refrigerant of two or more of these, or a mixed refrigerant of any of these with another refrigerant. Examples of the refrigerant 19 include a mixed refrigerant containing R1132(E) or a mixed refrigerant containing R1123. Examples of the refrigerant 19 include mixed refrigerants of R516A, R445A, R444A, R454C, R444B, R454A, R455A, R457A, R459B, R452B, R454B, R447B, R447A, R446A, and R459A.

[0017] The multiple circulating refrigerant circuits 110 are formed by connecting at least one indoor unit 20 to each of the multiple refrigerant circuit sections 80 provided in the outdoor unit 10 via a pair of refrigerant pipes 88a, 88b. In Embodiment 1, two circulating refrigerant circuits 110 are provided: a first circulating refrigerant circuit 110a and a second circulating refrigerant circuit 110b. In Embodiment 1, the outdoor unit 10 is provided with two refrigerant circuit sections 80: a first refrigerant circuit section 81 and a second refrigerant circuit section 82. The first circulating refrigerant circuit 110a is formed by connecting two first indoor units 20a to the first refrigerant circuit section 81 via a pair of refrigerant pipes 88a, 88b, respectively. The second circulating refrigerant circuit 110b is formed by connecting two second indoor units 20b to the second refrigerant circuit section 82 via a pair of refrigerant pipes 88a, 88b, respectively.

[0018] The air conditioner 100 can adjust the temperature of the air in each room by exchanging heat between the refrigerant 19 flowing in each circulating refrigerant circuit 110 and the air in each room where the indoor unit 20 is located. The circulating refrigerant circuits 110 are independent of each other, and the refrigerants 19 sealed in the circulating refrigerant circuits 110 do not mix with each other.

[0019] The outdoor unit 10 includes a housing 11, a heat exchanger 30, a blower 40, multiple compressors 50, multiple receivers 60, multiple four-way valves 70, multiple stop valves 85, and multiple expansion valves 86. As shown in Figures 2 and 3, the housing 11 is in the shape of a substantially rectangular parallelepiped box. The interior of the housing 11 is divided into a blower chamber 11a and a machine chamber 11b by a partition wall 11c. The blower chamber 11a is located adjacent to the machine chamber 11b on the left side (-Y side).

[0020] The blower chamber 11a houses a heat exchanger 30 and a blower 40. The blower 40 is, for example, a propeller fan. The blower 40 is located in front of the heat exchanger 30 (in the +X direction). The blower 40 is located downstream of the heat exchanger 30 in the direction of air flow generated by the blower 40. When the blower 40 is driven, outdoor air is drawn into the housing 11 through an air inlet (not shown) provided on the rear (-X side) surface of the housing 11, passes through the heat exchanger 30, and is blown out outdoors through an air outlet (not shown) provided on the front surface of the housing 11.

[0021] The machinery chamber 11b accommodates a plurality of compressors 50, a plurality of receivers 60, a plurality of four-way valves 70, a plurality of stop valves 85, and a plurality of expansion valves 86. Each component disposed in the machinery chamber 11b is positioned so as not to block the air path of the air sent by the blower 40.

[0022] In the heat exchanger 30, heat is exchanged between the refrigerant 19 flowing inside the heat exchanger 30 and the air outdoors where the outdoor unit 10 is located. As shown in FIG. 1 , in the first embodiment, the heat exchanger 30 has a first heat exchange section 31 and a second heat exchange section 32. A temperature sensor 33 is attached to the first heat exchange section 31. A temperature sensor 34 is attached to the second heat exchange section 32. The first heat exchange section 31 and the second heat exchange section 32 are arranged side by side. An airflow generated by a blower 40 passes through the heat exchanger 30. In the first embodiment, the airflow generated by one blower 40 passes through the first heat exchange section 31 and the second heat exchange section 32. The first heat exchange section 31 and the second heat exchange section 32 are independent of each other, and the refrigerants 19 flowing inside the respective heat exchange sections do not mix within the heat exchanger 30. The first heat exchange section 31 and the second heat exchange section 32 may be independent heat exchangers.

[0023] The compressor 50 pressurizes and delivers the refrigerant 19 into the circulating refrigerant circuit 110. In the first embodiment, two compressors 50 are provided: a first compressor 51 and a second compressor 52. As shown in FIG. 2 , the first compressor 51 and the second compressor 52 are located in a lower portion inside the machine chamber 11b. The first compressor 51 and the second compressor 52 are each surrounded by a cylindrical soundproofing material 12. The soundproofing material 12 is provided to prevent sound generated by driving each compressor 50 from leaking outside the housing 11.

[0024] Each compressor 50 is an inverter compressor. As shown in FIG. 4 , the first compressor 51 has a first compressor main body 51a and a first inverter circuit 51b. The first compressor main body 51a is a part that is capable of pumping the refrigerant 19 by receiving power from the first inverter circuit 51b. The second compressor 52 has a second compressor main body 52a and a second inverter circuit 52b. The second compressor main body 52a is a part that is capable of pumping the refrigerant 19 by receiving power from the second inverter circuit 52b. The first compressor main body 51a and the second compressor main body 52a each have a motor (not shown).

[0025] The first inverter circuit 51b supplies AC current to the first compressor main body 51a. The second inverter circuit 52b supplies AC current to the second compressor main body 52a. The frequency of the AC current supplied from each inverter circuit to each compressor main body is the operating frequency f of each compressor 50. The AC current supplied to each compressor main body is supplied to each motor provided in each compressor main body. The rotation speed of each motor is proportional to the frequency of the supplied AC current, i.e., the operating frequency f. The higher the rotation speed of each motor, the greater the amount of refrigerant 19 pumped per unit time from each compressor main body. The operating frequency f of each compressor 50 is appropriately adjusted depending on the air conditioning load of the indoor unit 20 to which the refrigerant 19 is pumped by each compressor 50. The air conditioning load of the indoor unit 20 is the amount of heat removed from or added to the room by the indoor unit 20 to adjust the room temperature to a set temperature. The air conditioning load of the indoor unit 20 increases, for example, as the difference between the set temperature of the indoor unit 20 and the room temperature increases, and decreases as the difference between the set temperature of the indoor unit 20 and the room temperature decreases.

[0026] The multiple receivers 60 are capable of storing the refrigerant 19 therein. The multiple receivers 60 may be any containers capable of storing the refrigerant 19 therein. The receivers 60 may be, for example, accumulators or receivers. The amount of refrigerant 19 circulating within the circulating refrigerant circuit 110 varies depending on the number of indoor units 20 in operation and the air conditioning load of each indoor unit 20. If the amount of refrigerant 19 circulating within the circulating refrigerant circuit 110 is greater than necessary, the operating capacity of each indoor unit 20 may be excessive, and problems such as breakdown of the circulating refrigerant circuit 110 may occur. Therefore, the excess refrigerant 19 is stored within the receivers 60.

[0027] As shown in FIG. 1 , in the first embodiment, the multiple receivers 60 are disposed on the discharge sides of the multiple compressors 50, respectively. In the first embodiment, two receivers 60 are provided: a first receiver 61 and a second receiver 62. As shown in FIG. 3 , the first receiver 61 and the first compressor 51 are disposed adjacent to each other in the machine room 11b. The first receiver 61 and the first compressor 51 are surrounded by a cylindrical soundproofing material 12. The second receiver 62 and the second compressor 52 are disposed adjacent to each other in the machine room 11b. The second receiver 62 and the second compressor 52 are surrounded by a cylindrical soundproofing material 12.

[0028] As shown in FIG. 1 , a plurality of four-way valves 70 are provided in a plurality of refrigerant circuit units 80, respectively. Each four-way valve 70 can reverse the direction of refrigerant 19 flowing through each refrigerant circuit unit 80 by switching a portion of the paths in each refrigerant circuit unit 80. When the paths connected by the four-way valve 70 are the paths shown by solid lines on the four-way valve 70 in FIG. 1 , the refrigerant 19 flows through the refrigerant circuit unit 80 in the direction shown by solid arrows in FIG. 1 . On the other hand, when the paths connected by the four-way valve 70 are the paths shown by dashed lines on the four-way valve 70 in FIG. 1 , the refrigerant 19 flows through the refrigerant circuit unit 80 in the direction shown by dashed arrows in FIG. 1 . In the first embodiment, two four-way valves 70 are provided: a first four-way valve 71 and a second four-way valve 72.

[0029] The first compressor 51, the first liquid receiver 61, and the first heat exchange section 31 of the heat exchanger 30 are connected by piping to form a first refrigerant circuit section 81. In the portion of the first refrigerant circuit section 81 on the discharge side of the first compressor 51, the first liquid receiver 61 and a first four-way valve 71 are provided in this order from the upstream side to the downstream side.

[0030] The second compressor 52, the second liquid receiver 62, and the second heat exchange section 32 of the heat exchanger 30 are connected by piping to form a second refrigerant circuit section 82. In the portion of the second refrigerant circuit section 82 on the discharge side of the second compressor 52, the second liquid receiver 62 and the second four-way valve 72 are provided in this order from the upstream side to the downstream side.

[0031] Each of the multiple refrigerant circuit sections 80 has a connection section 83 consisting of two connection pipes 83a, 83b. Two refrigerant pipes 88a, 88b extending from one indoor unit 20 can be connected to the two connection pipes 83a, 83b, respectively. In other words, one indoor unit 20 can be connected to one connection section 83. In Embodiment 1, the first refrigerant circuit section 81 and the second refrigerant circuit section 82 each have two connection sections 83. In other words, the refrigerant circuit sections 80 have the same number of connection sections 83 in Embodiment 1. In Embodiment 1, a maximum of two indoor units 20 can be connected to each of the first refrigerant circuit section 81 and the second refrigerant circuit section 82.

[0032] The number of connection parts 83 provided in each refrigerant circuit part 80, i.e., the number of indoor units 20 connectable to each refrigerant circuit part 80, is not particularly limited as long as it is one or more, and may be different from each other. In the air conditioner 100, the multiple connection parts 83 may include a connection part 83 to which no indoor unit 20 is connected. The types of indoor units 20 connected to each refrigerant circuit part 80 may be different from each other. When multiple indoor units 20 are connected to one refrigerant circuit part 80, the multiple indoor units 20 may include two or more indoor units 20 of different types from each other.

[0033] The connection pipes 83a of each connection unit 83 are each provided with an expansion valve 86. The expansion valves 86 are, for example, electronic expansion valves. One end of the connection pipes 83a of each connection unit 83 is connected to a refrigerant pipe 88a. The other end of the connection pipes 83a of the connection unit 83 provided in the first refrigerant circuit unit 81 is connected to a pipe section 83c extending from the first heat exchange unit 31. The two connection pipes 83a of the connection unit 83 provided in the first refrigerant circuit unit 81 branch off from the pipe section 83c. The other end of the connection pipes 83a of the connection unit 83 provided in the second refrigerant circuit unit 82 is connected to a pipe section 83e extending from the second heat exchange unit 32. The two connection pipes 83a of the connection unit 83 provided in the second refrigerant circuit unit 82 branch off from the pipe section 83e.

[0034] One end of the connection pipe 83b in each connection unit 83 is connected to a refrigerant pipe 88b. The other end of the connection pipe 83b in the connection unit 83 provided in the first refrigerant circuit unit 81 is connected to a pipe unit 83d extending from the first four-way valve 71. The two connection pipes 83b in the connection unit 83 provided in the first refrigerant circuit unit 81 branch off from the pipe unit 83d. The other end of the connection pipe 83b in the connection unit 83 provided in the second refrigerant circuit unit 82 is connected to a pipe unit 83f extending from the second four-way valve 72. The two connection pipes 83b in the connection unit 83 provided in the second refrigerant circuit unit 82 branch off from the pipe unit 83f. Stop valves 85 are provided in the pipe units 83c, 83d, 83e, and 83f, respectively. The stop valves 85 are valves that can shut off a portion of the refrigerant circuit unit 80. In the first embodiment, each stop valve 85 can block a part of each of the pipe sections 83c, 83d, 83e, and 83f.

[0035] The indoor units 20 connected to each refrigerant circuit section 80 are connected in parallel to one another. In each circulating refrigerant circuit 110, the refrigerant 19 branches off from the outdoor unit 10 to each of the indoor units 20, and the refrigerant 19 that has flowed through each of the indoor units 20 joins together in the outdoor unit 10.

[0036] The amount of refrigerant 19 sealed in the first refrigerant circuit section 81 is refrigerant amount α. The amount of refrigerant 19 sealed in the second refrigerant circuit section 82 is refrigerant amount β. The refrigerant amount α and the refrigerant amount β are different from each other. That is, the amounts of refrigerant 19 sealed in the multiple refrigerant circuit sections 80 are different from each other. The refrigerant amount β is, for example, greater than the refrigerant amount α. The amount of refrigerant 19 sealed in each refrigerant circuit section 80 is described, for example, on a nameplate sticker affixed to the housing 11 of the outdoor unit 10 or on the specifications of the air conditioner 100. Therefore, users can confirm the amount of refrigerant 19 sealed in each refrigerant circuit section 80 by looking at the nameplate sticker, the specifications, or the like. The ratio of the refrigerant amount β to the refrigerant amount α is, for example, approximately 1.2 to 3 times. The difference between the refrigerant amount α and the refrigerant amount β is preferably such that, when the output required to adjust the indoor temperature by each indoor unit 20 connected to each refrigerant circuit section 80 is the same, the operating frequency f of each compressor 50 provided in each refrigerant circuit section 80 differs by 3 Hz or more, and more preferably by 5 Hz or more.

[0037] The amount of refrigerant 19 sealed in each refrigerant circuit section 80 is the total amount of refrigerant 19 circulating in each circulating refrigerant circuit 110 formed by connecting at least one indoor unit 20 to each refrigerant circuit section 80. The amount of refrigerant 19 sealed in each refrigerant circuit section 80 is the total amount of refrigerant 19 present in each refrigerant circuit section 80 in the outdoor unit 10 when no refrigerant 19 is present inside the indoor unit 20 and inside the refrigerant pipes 88a, 88b, for example, before the air conditioner 100 is used. The amount of refrigerant 19 sealed in each refrigerant circuit section 80 is the total amount of refrigerant 19 present in each circulating refrigerant circuit 110 when the air conditioner 100 is used and refrigerant 19 is present inside the indoor unit 20 and inside the refrigerant pipes 88a, 88b.

[0038] Furthermore, for example, if the refrigerant 19 is sealed in each refrigerant circuit section 80 of the outdoor unit 10 before shipping the manufactured air conditioner 100, the total amount of refrigerant 19 sealed in each refrigerant circuit section 80 of the outdoor unit 10 at the time of shipping is the amount of refrigerant 19 sealed in each refrigerant circuit section 80. Furthermore, for example, if the refrigerant 19 is sealed in each refrigerant circuit section 80 of the outdoor unit 10 after shipping, such as at the site where the air conditioner 100 is installed, the total amount of refrigerant 19 sealed in each refrigerant circuit section 80 at that time is the amount of refrigerant 19 sealed in each refrigerant circuit section 80.

[0039] The amount of refrigerant 19 sealed in each refrigerant circuit section 80 is adjusted according to the capacity of the air conditioner 100 and the length of the pipe connecting the outdoor unit 10 and the indoor unit 20. Each refrigerant circuit section 80 is independent of the other, and the refrigerants 19 sealed in each refrigerant circuit section 80 do not mix with each other.

[0040] Each indoor unit 20 includes a heat exchanger 21, a blower 22, a temperature sensor 23, a housing 24, and an alarm 26. The housing 24 houses the heat exchanger 21 and the blower 22. Two refrigerant pipes 88a, 88b extend from the heat exchanger 21. The heat exchanger 21 in each indoor unit 20 is provided in the corresponding circulating refrigerant circuit 110 in which the indoor unit 20 is provided. The temperature sensor 23 is a sensor capable of detecting the temperature of the room in which the indoor unit 20 is located. The alarm 26 alerts the user to the occurrence of an abnormality, for example, in the event that an abnormality occurs in the indoor unit 20 or the refrigerant circuit section 80 to which the indoor unit 20 is connected. The alarm 26 alerts the user to the occurrence of the abnormality by, for example, using at least one of sound and light. The indoor unit 20 is capable of performing a cooling operation to cool the air in the room where the indoor unit 20 is placed, and a heating operation to warm the air in the room where the indoor unit 20 is placed.

[0041] When the indoor unit 20 is in cooling operation, the refrigerant 19 flowing in the circulating refrigerant circuit 110 in which the indoor unit 20 is provided flows in the direction shown by the solid arrow in Fig. 1. In other words, when the indoor unit 20 is in cooling operation, the refrigerant 19 flowing in the circulating refrigerant circuit 110 in which the indoor unit 20 is provided circulates through the compressor 50, the receiver 60, the heat exchanger 30 of the outdoor unit 10, the expansion valve 86, and the heat exchanger 21 of the indoor unit 20 in that order before returning to the compressor 50. During cooling operation, the heat exchanger 30 in the outdoor unit 10 functions as a condenser, and the heat exchanger 21 in the indoor unit 20 functions as an evaporator.

[0042] On the other hand, when the indoor unit 20 is in heating operation, the refrigerant 19 flowing in the circulating refrigerant circuit 110 in which the indoor unit 20 is provided flows in the direction shown by the dashed line in Fig. 1. In other words, when the indoor unit 20 is in heating operation, the refrigerant 19 flowing in the circulating refrigerant circuit 110 in which the indoor unit 20 is provided circulates through the compressor 50, the receiver 60, the heat exchanger 21 of the indoor unit 20, the expansion valve 86, and the heat exchanger 30 of the outdoor unit 10 in that order before returning to the compressor 50. In heating operation, the heat exchanger 30 in the outdoor unit 10 functions as an evaporator, and the heat exchanger 21 in the indoor unit 20 functions as a condenser.

[0043] As shown in Fig. 4, each indoor unit 20 is provided with an indoor unit control unit 25. Each first indoor unit 20a is provided with a first indoor unit control unit 25a. Each second indoor unit 20b is provided with a second indoor unit control unit 25b.

[0044] The outdoor unit 10 includes a control device 90a. The control device 90a controls a plurality of refrigerant circuit units 80. In the first embodiment, the control device 90a includes an outdoor unit control unit 90, a power supply control unit 93, and an electric equipment box 95. The outdoor unit control unit 90 and the power supply control unit 93 are housed inside the electric equipment box 95. The electric equipment box 95 is housed, for example, in the machine chamber 11b of the housing 11.

[0045] The power supply control unit 93 receives power from an external power supply 94. The external power supply 94 is, for example, a commercial power supply or a household power supply. The power supply control unit 93 supplies the power received from the external power supply 94 to the outdoor unit 10 and the indoor units 20. More specifically, the power supply control unit 93 supplies power to the outdoor unit control unit 90, each indoor unit control unit 25, and each inverter circuit unit of the compressors 50. The power supply control unit 93 includes a relay circuit for supplying power to each unit. The power supply control unit 93 can turn the power supply to each unit on and off by switching the relay circuit. The power supply control unit 93 may be provided on a different board from the board on which the outdoor unit control unit 90 is provided, or may be provided on the same board as the board on which the outdoor unit control unit 90 is provided. The power supply control unit 93 may be provided separately from the control device 90a.

[0046] The power supply control unit 93 is capable of supplying power to indoor units 20 connected to some refrigerant circuit units 80, while stopping the supply of power to indoor units 20 connected to other refrigerant circuit units 80. Specifically, when the power supply control unit 93 determines, based on a signal from the outdoor unit control unit 90, that there is a refrigerant circuit unit 80 that has been stopped operating for a relatively long period of time, it stops the supply of power to the indoor units 20 connected to that refrigerant circuit unit 80. This causes the indoor unit 20 to enter a first standby mode. The first standby mode is a mode in which only operation commands can be accepted using power stored in a capacitor mounted in the indoor unit control unit 25 of the indoor unit 20. When an operation command is input by a user or the like to an indoor unit 20 that has entered the first standby mode, a signal is sent from the indoor unit control unit 25 to the power supply control unit 93 via the outdoor unit control unit 90, and the power supply control unit 93 resumes supplying power to the indoor unit 20. When the power supply control unit 93 stops the supply of power to all indoor units 20 connected to a certain refrigerant circuit unit 80, it also stops the supply of power to the compressor 50 provided in that certain refrigerant circuit unit 80.

[0047] The outdoor unit control unit 90 is, for example, a system control unit that oversees the overall control of the air conditioner 100. The outdoor unit control unit 90 is capable of wireless or wired communication with each indoor unit control unit 25. The outdoor unit control unit 90 is capable of controlling the blower 22 of each indoor unit 20 by sending a signal to each indoor unit control unit 25. The outdoor unit control unit 90 is capable of controlling the blower 40 of the outdoor unit 10.

[0048] The outdoor unit control unit 90 controls the multiple refrigerant circuit units 80. Specifically, the outdoor unit control unit 90 controls the compressors 50, four-way valves 70, stop valves 85, and expansion valves 86 provided in each refrigerant circuit unit 80. The outdoor unit control unit 90 is capable of wireless or wired communication with the power supply control unit 93, the first inverter circuit unit 51b, and the second inverter circuit unit 52b. The outdoor unit control unit 90 outputs command values ​​for the operating frequency f of each compressor 50 to the first inverter circuit unit 51b and the second inverter circuit unit 52b. The first inverter circuit unit 51b and the second inverter circuit unit 52b supply AC current to the motors of the compressor main bodies based on the input command values. This drives each compressor 50.

[0049] FIG. 5 is a graph showing an example of changes in the operating frequency f of each compressor 50 controlled by the outdoor unit control unit 90. The upper graph in FIG. 5 is a graph showing an example of changes in the operating frequency f1 of the first compressor 51. The lower graph in FIG. 5 is a graph showing an example of changes in the operating frequency f2 of the second compressor 52. In both the upper and lower graphs in FIG. 5, the horizontal axis represents time t and the vertical axis represents the operating frequency f. FIG. 5 shows an example in which each compressor 50 starts operating at time t11 and stops at time t15. In the example of FIG. 5, at time t11, the temperatures in the first room R1 and the second room R2 are the same, and the set temperatures of each indoor unit 20 are also the same. In the example of FIG. 5, the indoor units 20 arranged in the first room R1 and the second room R2, respectively, adjust the temperatures of the respective rooms with similar outputs.

[0050] In the example of the upper graph in Fig. 5, the operating frequency f1 of the first compressor 51 begins to increase linearly from time t11 and increases to frequency fd. The operating frequency f1 of the first compressor 51 is maintained at frequency fd until time t12, and then begins to decrease from time t12 to frequency fc, which is lower than frequency fd. After being maintained at frequency fc for a while, the operating frequency f1 of the first compressor 51 increases again and reaches frequency fd again at time t13. The operating frequency f1 of the first compressor 51 is maintained at frequency fd until time t14, and then decreases to 0 Hz between time t14 and time t15.

[0051] In the example of the lower graph in FIG. 5 , the operating frequency f2 of the second compressor 52 begins to increase linearly from time t11 and rises to frequency fb, which is lower than frequency fd and frequency fc. The operating frequency f2 of the second compressor 52 is maintained at frequency fb until time t12, at which point it begins to decrease and drops to frequency fa, which is lower than frequency fb. The operating frequency f2 of the second compressor 52 is maintained at frequency fa for a while, then increases again and reaches frequency fb again at time t13. The operating frequency f2 of the second compressor 52 is maintained at frequency fb until time t14, then drops to 0 Hz between time t14 and time t15. As such, in Embodiment 1, when each indoor unit 20 is operated at the same output, the operating frequency f2 of the second compressor 52 provided in the second refrigerant circuit section 82 is lower than the operating frequency f1 of the first compressor 51 provided in the first refrigerant circuit section 81.

[0052] For the same operating frequency f of the compressor 50, the greater the amount of refrigerant 19 sealed in the refrigerant circuit section 80 in which the compressor 50 is provided, the greater the amount of refrigerant 19 pumped per unit time by the compressor 50. In other words, for the same amount of refrigerant 19 pumped per unit time by the compressor 50, the greater the amount of refrigerant 19 sealed in the refrigerant circuit section 80 in which the compressor 50 is provided, the lower the operating frequency f of the compressor 50. Therefore, for the same output required for adjusting the indoor temperature by the indoor unit 20, as illustrated in FIG. 5 , the operating frequency f2 of the second compressor 52 provided in the second refrigerant circuit section 82 in which a larger amount of refrigerant 19 is sealed than in the first refrigerant circuit section 81 will be lower than the operating frequency f1 of the first compressor 51.

[0053] The outdoor unit control unit 90 can cause each circulating refrigerant circuit 110 to perform defrosting operation to remove frost that has formed on the heat exchanger 30 based on the temperature obtained by the temperature sensors 33, 34 attached to the heat exchanger 30.

[0054] During the heating operation described above, the refrigerant 19 flowing through the heat exchanger 30 of the outdoor unit 10, which functions as an evaporator, absorbs heat from the air that contacts the heat exchanger 30. Therefore, the temperature of the heat exchanger 30 drops during the heating operation. In this case, for example, if the outdoor temperature where the outdoor unit 10 is located is relatively low and the outdoor humidity is relatively high, the moisture in the air that contacts the heat exchanger 30 reaches its dew point temperature, condenses, and adheres to the surface of the heat exchanger 30. When the temperature of the moisture adhered to the surface of the heat exchanger 30 drops below the freezing point, the moisture freezes and forms frost.

[0055] During defrosting operation, the flow direction of the refrigerant 19 in each circulating refrigerant circuit 110 is the same as the flow direction of the refrigerant 19 in each circulating refrigerant circuit 110 during cooling operation. During defrosting operation, as in cooling operation, the heat exchanger 30 in the outdoor unit 10 functions as a condenser, and the heat exchanger 21 in the indoor unit 20 functions as an evaporator. When refrigerant 19 is caused to flow as in the defrosting operation and cooling operation described above, refrigerant 19 at a relatively high temperature flows into the heat exchanger 30, and the refrigerant 19 releases heat to the air that comes into contact with the heat exchanger 30. Therefore, by causing the refrigerant 19 to flow in the same direction during defrosting operation as during cooling operation, the heat released from the refrigerant 19 flowing inside the heat exchanger 30 can melt and remove frost that has formed on the surface of the heat exchanger 30.

[0056] A plurality of operation modes are provided for the plurality of refrigerant circuit units 80. In the first embodiment, three operation modes are provided for the plurality of refrigerant circuit units 80: a cooling operation mode when the above-described cooling operation is performed, a heating operation mode when the above-described heating operation is performed, and a defrosting operation mode when the above-described defrosting operation is performed. The outdoor unit control unit 90 of the control device 90a can operate each refrigerant circuit unit 80 in an operation mode different from the operation modes of the other refrigerant circuit units 80.

[0057] The outdoor unit control unit 90 of the control device 90a controls each refrigerant circuit unit 80 based on information about the other refrigerant circuit units 80. The information about the refrigerant circuit unit 80 is not particularly limited as long as it is information related to the refrigerant circuit unit 80. The information about the refrigerant circuit unit 80 includes, for example, the operating frequency f of the compressor 50 provided in the refrigerant circuit unit 80, information about the indoor unit 20 connected to the refrigerant circuit unit 80, the amount of refrigerant 19 sealed in the refrigerant circuit unit 80, and the temperature of the heat exchanger 30 provided in the refrigerant circuit unit 80. The information about the indoor unit 20 connected to the refrigerant circuit unit 80 includes the operating status of the indoor unit 20, the set temperature of the indoor unit 20, and the temperature of the room in which the indoor unit 20 is located.

[0058] In the first embodiment, the outdoor unit control unit 90 of the control device 90a can determine the operation mode of each refrigerant circuit unit 80 based on information about the other refrigerant circuit units 80. For example, the outdoor unit control unit 90 can determine whether to set both the first refrigerant circuit unit 81 and the second refrigerant circuit unit 82 to the defrosting operation mode or to set only one of the first refrigerant circuit unit 81 and the second refrigerant circuit unit 82 to the defrosting operation mode based on temperature information about the heat exchanger 30 obtained from the temperature sensors 33 and 34. For example, when the outdoor unit control unit 90 determines, based on the temperature information about the heat exchanger 30 obtained from the temperature sensors 33 and 34, that the temperature of the heat exchanger 30 is lower than a predetermined first threshold value and equal to or higher than a predetermined second threshold value, it operates only the refrigerant circuit unit 80 provided with the heat exchange unit to which the temperature sensor 33 or the temperature sensor 34, whichever outputs the lower temperature information, is attached in the defrosting operation mode. In this case, the refrigerant circuit unit 80 that is not operated in the defrosting operation mode is, for example, stopped. For example, when the outdoor unit control unit 90 determines that the temperature of the heat exchanger 30 is lower than the second threshold value based on the temperature information of the heat exchanger 30 obtained from the temperature sensors 33 and 34, it operates both the first refrigerant circuit unit 81 and the second refrigerant circuit unit 82 in the defrosting operation mode. The second threshold value is a value lower than the first threshold value.

[0059] When the operation of one of the refrigerant circuit sections 80 stops abnormally, the outdoor unit control section 90 of the control device 90a can continue the operation of the other refrigerant circuit sections 80. When the operation of one of the refrigerant circuit sections 80 stops abnormally, the outdoor unit control section 90 may determine whether the abnormal stop of the operation of the one of the refrigerant circuit sections 80 has affected the other refrigerant circuit sections 80, and may continue the operation of the other refrigerant circuit sections 80 if it determines that there is no effect.

[0060] When the operation of some of the refrigerant circuit units 80 abnormally stops, the outdoor unit control unit 90 of the control device 90a notifies that an abnormality has occurred in some of the refrigerant circuit units 80. In Embodiment 1, the outdoor unit control unit 90 sends a signal to the notification unit 26 of the indoor unit 20 to notify the abnormality. The outdoor unit control unit 90 may notify the abnormality only to the notification unit 26 of the indoor unit 20 connected to the refrigerant circuit unit 80 in which the abnormality has occurred, or may notify the notification unit 26 of all of the indoor units 20.

[0061] When the operation of a certain indoor unit 20 is stopped, the outdoor unit control unit 90 fully closes the expansion valve 86 provided in the connection pipe 83a of the connection part 83 to which the certain indoor unit 20 is connected. As a result, the refrigerant 19 does not flow from the outdoor unit 10 into the indoor unit 20 whose operation is stopped.

[0062] According to the first embodiment, the outdoor unit 10 is an outdoor unit of the air conditioner 100 and is an outdoor unit to which multiple indoor units 20 are connected. The outdoor unit 10 includes multiple refrigerant circuit sections 80, each connected to at least one indoor unit 20, and multiple compressors 50 provided in the multiple refrigerant circuit sections 80. The amounts of refrigerant 19 sealed in the multiple refrigerant circuit sections 80 are different from one another. Therefore, as described above, when the same amount of refrigerant 19 is pumped per unit time, the operating frequencies f of the multiple compressors 50 are different from one another. This prevents the multiple compressors 50 provided in the outdoor unit 10 from being simultaneously driven at the same operating frequency f, for example, when the indoor units 20 provided in the multiple refrigerant circuit sections 80 are operated at the same output. This prevents resonance between the multiple compressors 50, thereby preventing abnormal noise from the outdoor unit 10.

[0063] Furthermore, because multiple refrigerant circuit sections 80 are provided, the amount of refrigerant 19 required in each refrigerant circuit section 80 can be reduced compared to when all indoor units 20 are connected to a single refrigerant circuit section 80. This reduces the performance required of each compressor 50 that compresses and sends the refrigerant 19 in each refrigerant circuit section 80, allowing for the miniaturization of each compressor 50. Furthermore, because the amount of refrigerant 19 sealed in each refrigerant circuit section 80 can be reduced, each receiver 60 that stores excess refrigerant 19 can also be made smaller.

[0064] Furthermore, according to the first embodiment, the outdoor unit 10 is equipped with a control device 90a that controls the multiple refrigerant circuit sections 80. The control device 90a controls each refrigerant circuit section 80 based on information related to the other refrigerant circuit sections 80. Therefore, by adjusting the operating frequency f of each compressor 50 provided in each refrigerant circuit section 80 according to the operating status of each refrigerant circuit section 80, it is possible to easily prevent the multiple compressors 50 from being driven simultaneously at the same operating frequency f. This makes it possible to further suppress resonance between the multiple compressors 50, and to further suppress abnormal noise from being generated from the outdoor unit 10.

[0065] Furthermore, according to the first embodiment, the outdoor unit 10 includes a power supply control unit 93 that supplies power to multiple indoor units 20. The power supply control unit 93 is capable of supplying power to indoor units 20 connected to some of the refrigerant circuit units 80, while stopping the supply of power to indoor units 20 connected to other refrigerant circuit units 80. As a result, some of the indoor units 20 can be driven while the other indoor units 20 are placed in a first standby mode in which power is not supplied from the power supply control unit 93. This reduces the power consumption of the air conditioner 100. Note that when only one refrigerant circuit unit 80 is provided, all of the indoor units 20 are connected to that single refrigerant circuit unit 80, and therefore, even when only some of the indoor units 20 are operated, power is supplied to all of the indoor units 20. In the first embodiment, multiple independent refrigerant circuit units 80 are provided, making it possible to supply power only to the indoor units 20 connected to some of the refrigerant circuit units 80.

[0066] Furthermore, according to the first embodiment, a plurality of operation modes are provided for the plurality of refrigerant circuit sections 80. The control device 90a can operate each refrigerant circuit section 80 in an operation mode different from the operation modes of the other refrigerant circuit sections 80. Therefore, it is possible to cause the indoor units 20 connected to each of the plurality of refrigerant circuit sections 80 to perform different operations. This allows the indoor units 20 located in different rooms to perform different operations, making it possible to appropriately adjust the room temperature for each room.

[0067] Furthermore, according to the first embodiment, the control device 90a can determine the operation mode of each refrigerant circuit unit 80 based on information about the other refrigerant circuit units 80. Therefore, the operation mode of each refrigerant circuit unit 80 can be easily determined appropriately while taking into consideration the load and power consumption of the air conditioner 100. Specifically, as described above, when it is necessary to remove frost from the heat exchanger 30, it is possible to select whether to cause all of the multiple refrigerant circuit units 80 to execute the defrosting operation mode or only some of the refrigerant circuit units 80 to execute the defrosting operation mode, taking into consideration the air conditioning load and the capacity required to remove frost. In the defrosting operation mode, the flow of the refrigerant 19 becomes the same as during cooling operation, and the heat exchanger 21 of the indoor unit 20 functions as an evaporator. Therefore, there is a risk of the temperature in the room where the indoor unit 20 is located dropping. Therefore, when it is not necessary to set all of the refrigerant circuit units 80 to the defrosting operation mode, it is possible to prevent a drop in the temperature in the room where the indoor units 20 connected to the other refrigerant circuit units 80 are located by setting the operation of only some of the refrigerant circuit units 80 to the defrosting operation mode and stopping the operation of the other refrigerant circuit units 80. This makes it possible to improve the comfort of the room where the indoor units 20 connected to the other refrigerant circuit units 80 are located.

[0068] Furthermore, according to the first embodiment, when the operation of one of the refrigerant circuit sections 80 is abnormally stopped, the control device 90a can continue the operation of the other refrigerant circuit sections 80. Therefore, even if an abnormality occurs in one of the refrigerant circuit sections 80, the indoor units 20 connected to the refrigerant circuit sections 80 that are not abnormal can be operated normally, and a decrease in comfort in the room in which the indoor units 20 are located can be suppressed.

[0069] Furthermore, according to the first embodiment, when the operation of some of the refrigerant circuit units 80 has abnormally stopped, the control device 90a notifies the user that an abnormality has occurred in some of the refrigerant circuit units 80. This makes it easy to quickly notify the user or the like that an abnormality has occurred in some of the refrigerant circuit units 80.

[0070] Furthermore, according to the first embodiment, each of the multiple refrigerant circuit sections 80 has a connection section 83 consisting of two connection pipes 83a, 83b. Two refrigerant pipes 88a, 88b extending from one indoor unit 20 can be connected to the two connection pipes 83a, 83b, respectively. The number of connection sections 83 included in each refrigerant circuit section 80 is the same. Therefore, the number of indoor units 20 that can be connected to each of the multiple refrigerant circuit sections 80 is the same. In such a case, the maximum number of indoor units 20 that can be connected to each refrigerant circuit section 80 is the same. Therefore, conventionally, the amount of refrigerant 19 sealed in each refrigerant circuit section 80 has also been the same. In contrast, in the first embodiment, by intentionally differentiating the amount of refrigerant 19 sealed in multiple refrigerant circuit sections 80 that have the same number of connectable indoor units 20, it is possible to easily differentiate the operating frequencies f of the compressors 50 provided in each refrigerant circuit section 80, as described above. Therefore, it is possible to prevent the plurality of compressors 50 from resonating with each other, and it is possible to prevent abnormal noise from being generated from the outdoor unit 10.

[0071] Embodiment 2. Fig. 6 is a schematic diagram showing the general configuration of an air conditioner 200 in embodiment 2. Fig. 7 is a block diagram showing part of the functional configuration of the air conditioner 200 in embodiment 2. In the following description, components similar to those in the above-described embodiments may be denoted by the same reference numerals as appropriate, and description thereof may be omitted.

[0072] As shown in FIGS. 6 and 7 , in the outdoor unit 210 of the air conditioner 200 of the second embodiment, the control device 290a has multiple outdoor unit control units 290, one for each of the multiple refrigerant circuit units 80. The multiple outdoor unit control units 290 are capable of independently controlling the multiple refrigerant circuit units 80. In the present disclosure, "the multiple outdoor unit control units 290 are capable of independently controlling the multiple refrigerant circuit units 80" means that each outdoor unit control unit 290 can control each refrigerant circuit unit 80 without receiving a control command from another outdoor unit control unit 290, and each outdoor unit control unit 290 can control each refrigerant circuit unit 80 even when the other outdoor unit control units 290 and the other refrigerant circuit units 80 are not operating. In the second embodiment, the amount of refrigerant 19 sealed in the first refrigerant circuit unit 81 and the amount of refrigerant 19 sealed in the second refrigerant circuit unit 82 are refrigerant amounts α and are the same.

[0073] In the second embodiment, two outdoor unit control sections 290 are provided: a first outdoor unit control section 291 and a second outdoor unit control section 292. The first outdoor unit control section 291 controls the first refrigerant circuit section 81 and the first indoor unit 20a connected to the first refrigerant circuit section 81. The second outdoor unit control section 292 controls the second refrigerant circuit section 82 and the second indoor unit 20b connected to the second refrigerant circuit section 82. The first outdoor unit control section 291 and the second outdoor unit control section 292 may be provided on the same board or on different boards.

[0074] As shown in FIG. 7 , the first outdoor unit control unit 291 and the second outdoor unit control unit 292 can communicate with each other wirelessly or via a wired connection. The first outdoor unit control unit 291 and the second outdoor unit control unit 292 can control each indoor unit 20 and each refrigerant circuit unit 80 while mutually monitoring the operating status of the other. The first outdoor unit control unit 291 can communicate wirelessly or via a wired connection with the first indoor unit control units 25a of the two first indoor units 20a connected to the first refrigerant circuit unit 81. The second outdoor unit control unit 292 can communicate wirelessly or via a wired connection with the second indoor unit control units 25b of the two second indoor units 20b connected to the second refrigerant circuit unit 82. The first outdoor unit control unit 291 and the second outdoor unit control unit 292 can each communicate wirelessly or via a wired connection with the power supply control unit 293. The first outdoor unit control unit 291 can communicate wirelessly or via a wired connection with the first inverter circuit unit 51b of the first compressor 51. The second outdoor unit control unit 292 is capable of communicating with the second inverter circuit unit 52b of the second compressor 52 wirelessly or via a wire.

[0075] In the second embodiment, each outdoor unit control unit 290 controls each refrigerant circuit unit 80 based on information relating to the other refrigerant circuit units 80 obtained from the other outdoor unit control units 290. In the second embodiment, the first outdoor unit control unit 291 and the second outdoor unit control unit 292 can perform control similar to that performed by the outdoor unit control unit 90 in the first embodiment described above by obtaining information from each other's outdoor unit control units 290.

[0076] Each outdoor unit control unit 290 can continue operation of the corresponding refrigerant circuit unit 80 when the operation of another refrigerant circuit unit 80 controlled by the other outdoor unit control unit 290 stops abnormally. In the second embodiment, for example, the first outdoor unit control unit 291 can continue operation of the first refrigerant circuit unit 81 when the operation of the second refrigerant circuit unit 82 controlled by the second outdoor unit control unit 292 stops abnormally. In this case, the first outdoor unit control unit 291, like the outdoor unit control unit 90 in the first embodiment, notifies the notification unit 26 that an abnormality has occurred in the second refrigerant circuit unit 82. In the second embodiment, each outdoor unit control unit 290 can continue operation of the corresponding refrigerant circuit unit 80 even when the other outdoor unit control unit 290 stops abnormally. Even in this case, each outdoor unit control unit 290 notifies the notification unit 26 that an abnormality has occurred in the other outdoor unit control unit 290.

[0077] The control device 290a controls each compressor 50 so that the timings at which the compressors 50 start to be driven are shifted from one another. In the second embodiment, each outdoor unit control unit 290 controls each compressor 50 based on information relating to the other refrigerant circuit units 80 obtained from the other outdoor unit control units 290 so that the timings at which the compressors 50 start to be driven are shifted from one another.

[0078] The control device 290a controls each compressor 50 so that the operating frequencies f of the compressors 50 are different from one another. In the second embodiment, each outdoor unit control unit 290 adjusts the operating frequency f of each compressor 50 based on information relating to the other refrigerant circuit units 80 obtained from the other outdoor unit control units 290, so that the operating frequencies f of the compressors 50 are different from one another.

[0079] An example of control performed by each outdoor unit control unit 290 will be described in detail below. In the following description, control by the first outdoor unit control unit 291 will be described as a representative example, and a description of control by the second outdoor unit control unit 292 may be omitted. Fig. 8 is a flowchart showing an example of a control procedure performed by the first outdoor unit control unit 291 before driving the first compressor 51. Fig. 9 is a flowchart showing an example of a control procedure when the first outdoor unit control unit 291 adjusts the operating frequency f of the first compressor 51.

[0080] 8, when an operation start signal to start operation is input to the first indoor unit 20a (step S11), the first outdoor unit control unit 291 sends a signal to the first indoor unit control unit 25a based on the operation start signal input from the first indoor unit control unit 25a, and drives the blower 22 of the first indoor unit 20a (step S12). Note that in step S12, the first indoor unit control unit 25a may drive the blower 22 without going through the first outdoor unit control unit 291.

[0081] The first outdoor unit control unit 291 checks whether an operation start signal has been input to the second indoor unit 20b (step S13). In step S13, the first outdoor unit control unit 291 determines whether an operation start signal has been input to the second indoor unit 20b based on information related to the second indoor unit 20b obtained from the second outdoor unit control unit 292. If it is determined in step S13 that an operation start signal has not been input to the second indoor unit 20b (step S13: NO), the first outdoor unit control unit 291 drives the first compressor 51 (step S17).

[0082] If it is determined in step S13 that an operation start signal has been input to the second indoor unit 20b (step S13: YES), the first outdoor unit control unit 291 determines whether or not the second compressor 52 of the second refrigerant circuit unit 82 is driven (step S14). In step S14, the first outdoor unit control unit 291 determines whether or not the second compressor 52 is driven based on information about the second compressor 52 obtained from the second outdoor unit control unit 292.

[0083] If the second compressor 52 is not driven in step S14 (step S14: NO), the first outdoor unit control unit 291 determines whether the difference between the set temperature Ts2 of the second indoor unit 20b and the temperature Tr2 in the second room R2 is smaller than the difference between the set temperature Ts1 of the first indoor unit 20a and the temperature Tr1 in the first room R1 (step S16). In step S16, the first outdoor unit control unit 291 obtains the temperature Tr1 in the first room R1 based on the temperature sensor 23 provided in the first indoor unit 20a, and obtains the set temperature Ts1 of the first indoor unit 20a based on information from the first indoor unit control unit 25a. In step S14, the first outdoor unit control unit 291 obtains the temperature Tr2 in the second room R2 and the set temperature Ts2 of the second indoor unit 20b based on information about the second indoor unit 20b obtained from the second outdoor unit control unit 292. The second outdoor unit control section 292 acquires the temperature Tr2 in the second room R2 based on the temperature sensor 23 provided in the second indoor unit 20b.

[0084] If, in step S16, the difference between the set temperature Ts2 of the second indoor unit 20b and the temperature Tr2 in the second room R2 is greater than the difference between the set temperature Ts1 of the first indoor unit 20a and the temperature Tr1 in the first room R1 (step S16: NO), the first outdoor unit control unit 291 returns to the determination in step S14. On the other hand, if, in step S16, the difference between the set temperature Ts2 of the second indoor unit 20b and the temperature Tr2 in the second room R2 is smaller than the difference between the set temperature Ts1 of the first indoor unit 20a and the temperature Tr1 in the first room R1 (step S16: YES), the first outdoor unit control unit 291 drives the first compressor 51 (step S17).

[0085] In addition, when an operation start signal is input to each of the first indoor unit 20a and the second indoor unit 20b and neither the first compressor 51 nor the second compressor 52 is driven, if the difference between the set temperature Ts2 of the second indoor unit 20b and the temperature Tr2 in the second chamber R2 is the same as the difference between the set temperature Ts1 of the first indoor unit 20a and the temperature Tr1 in the first chamber R1, for example, the compressor 50 that has been determined in advance to be driven preferentially between the first compressor 51 and the second compressor 52 will be driven.

[0086] If the second compressor 52 is being driven in step S14 (step S14: YES), the first outdoor unit control unit 291 determines whether the start-up period RP of the second compressor 52 has ended (step S15). The start-up period RP of the compressor 50 is the period from when a command to start driving the stopped compressor 50 is input until the operating frequency f of the compressor 50 reaches a steady-state value based on the input command value. In step S15, the first outdoor unit control unit 291 determines whether the start-up period RP of the second compressor 52 has ended, based on information about the second compressor 52 obtained from the second outdoor unit control unit 292.

[0087] If the start-up period RP of the second compressor 52 has not ended in step S15 (step S15: NO), the first outdoor unit control unit 291 performs the determination in step S15 again without driving the first compressor 51. On the other hand, if the start-up period RP of the second compressor 52 has ended in step S15 (step S15: YES), the first outdoor unit control unit 291 performs the above-mentioned step S16. Note that when performing step S16 after going through step S15, if the difference between the set temperature Ts2 of the second indoor unit 20b and the temperature Tr2 in the second room R2 is equal to or greater than the difference between the set temperature Ts1 of the first indoor unit 20a and the temperature Tr1 in the first room R1, the first outdoor unit control unit 291 may perform step S16 again without returning to step S14.

[0088] The first outdoor unit control unit 291 performs control as in steps S11 to S17 described above, thereby shifting the timing at which the first compressor 51 starts to be driven relative to the timing at which the second compressor 52 starts to be driven. The second outdoor unit control unit 292 also performs control similar to that of the first outdoor unit control unit 291, thereby shifting the timing at which the second compressor 52 starts to be driven relative to the timing at which the first compressor 51 starts to be driven. In this way, each outdoor unit control unit 290 controls each compressor 50 so that the timings at which the compressors 50 start to be driven are shifted relative to each other, based on information about other refrigerant circuit units 80 obtained from the other outdoor unit control units 290.

[0089] As shown in FIG. 9 , after driving the first compressor 51 (step S17), the first outdoor unit control unit 291 determines whether the operating frequency f1 of the first compressor 51 is the same as the operating frequency f2 of the second compressor 52 (step S18). In step S18, the first outdoor unit control unit 291 obtains the operating frequency f2 of the second compressor 52 from the second outdoor unit control unit 292. If the operating frequency f1 of the first compressor 51 is the same as the operating frequency f2 of the second compressor 52 in step S18 (step S18: YES), the first outdoor unit control unit 291 determines whether the difference between the set temperature Ts2 of the second indoor unit 20b and the temperature Tr2 in the second room R2 is greater than the difference between the set temperature Ts1 of the first indoor unit 20a and the temperature Tr1 in the first room R1 (step S19). In step S19, the first outdoor unit control unit 291 obtains each value in the same manner as in step S16.

[0090] In step S19, if the difference between the set temperature Ts2 of the second indoor unit 20b and the temperature Tr2 in the second room R2 is greater than the difference between the set temperature Ts1 of the first indoor unit 20a and the temperature Tr1 in the first room R1 (step S19: YES), the first outdoor unit control unit 291 lowers the operating frequency f1 of the first compressor 51 (step S20). As a result, the operating frequency f1 of the first compressor 51 becomes a frequency different from the operating frequency f2 of the second compressor 52.

[0091] Through steps S18, S19, and S20, the first outdoor unit control unit 291 can adjust the operating frequency f1 of the first compressor 51 so that the operating frequency f1 of the first compressor 51 differs from the operating frequency f2 of the second compressor 52, based on information about the second refrigerant circuit unit 82 obtained from the second outdoor unit control unit 292. The second outdoor unit control unit 292 can also adjust the operating frequency f2 of the second compressor 52 so that the operating frequency f2 of the second compressor 52 differs from the operating frequency f1 of the first compressor 51, by performing control similar to that of the first outdoor unit control unit 291. In this way, each outdoor unit control unit 290 adjusts the operating frequency f of each compressor 50 so that the operating frequencies f of the compressors 50 differ from one another, based on information about the other refrigerant circuit units 80 obtained from the other outdoor unit control units 290.

[0092] The reduction amount when the operating frequency f1 of the first compressor 51 is reduced in step S20 is, for example, predetermined and stored in the first outdoor unit control unit 291. From the viewpoint of suppressing resonance between the first compressor 51 and the second compressor 52, the reduction amount of the operating frequency f is preferably 3 Hz or more, and more preferably 5 Hz or more.

[0093] In step S19, if the difference between the set temperature Ts2 of the second indoor unit 20b and the temperature Tr2 in the second room R2 is less than or equal to the difference between the set temperature Ts1 of the first indoor unit 20a and the temperature Tr1 in the first room R1 (step S19: NO), the first outdoor unit control unit 291 performs step S18 again.

[0094] If the operating frequency f1 of the first compressor 51 is different from the operating frequency f2 of the second compressor 52 in step S18 (step S18: NO), the first outdoor unit control unit 291 determines whether the operating frequency f1 of the first compressor 51 is lower than the operating frequency f2 of the second compressor 52 (step S21). If the operating frequency f1 of the first compressor 51 is higher than the operating frequency f2 of the second compressor 52 in step S21 (step S21: NO), the first outdoor unit control unit 291 performs step S18 again.

[0095] If the operating frequency f1 of the first compressor 51 is lower than the operating frequency f2 of the second compressor 52 in step S21 (step S21: YES), the first outdoor unit control unit 291 determines whether the difference between the set temperature Ts2 of the second indoor unit 20b and the temperature Tr2 in the second room R2 is smaller than the difference between the set temperature Ts1 of the first indoor unit 20a and the temperature Tr1 in the first room R1 (step S22). In step S22, the first outdoor unit control unit 291 acquires each value in the same manner as in step S16.

[0096] If, in step S22, the difference between the set temperature Ts2 of the second indoor unit 20b and the temperature Tr2 in the second room R2 is smaller than the difference between the set temperature Ts1 of the first indoor unit 20a and the temperature Tr1 in the first room R1 (step S22: YES), the first outdoor unit control unit 291 increases the operating frequency f1 of the first compressor 51 (step S23). The increase amount by which the operating frequency f1 of the first compressor 51 is increased in step S23 is, for example, determined in advance and stored in the first outdoor unit control unit 291. The increase amount by which the operating frequency f is increased may be the same as or different from the decrease amount by which the operating frequency f was decreased in step S20.

[0097] In step S22, if the difference between the set temperature Ts2 of the second indoor unit 20b and the temperature Tr2 in the second room R2 is greater than or equal to the difference between the set temperature Ts1 of the first indoor unit 20a and the temperature Tr1 in the first room R1 (step S22: NO), the first outdoor unit control unit 291 performs step S18 again.

[0098] In steps S18 to S23, the first outdoor unit control unit 291 adjusts the operating frequency f1 of the first compressor 51 based on information relating to the second refrigerant circuit unit 82 obtained from the second outdoor unit control unit 292. The second outdoor unit control unit 292 also adjusts the operating frequency f2 of the second compressor 52 by performing control similar to that of the first outdoor unit control unit 291. In this way, each outdoor unit control unit 290 adjusts the operating frequency f of each compressor 50 based on information relating to the other refrigerant circuit units 80 obtained from the other outdoor unit control units 290.

[0099] In step S18, it may be determined whether the difference between the operating frequency f1 of the first compressor 51 and the operating frequency f2 of the second compressor 52 is equal to or less than a predetermined value. The predetermined value is, for example, approximately 3 Hz to 5 Hz. In this case, the first outdoor unit control unit 291 and the second outdoor unit control unit 292 can shift the operating frequencies f of the compressors 50 not only when the operating frequencies f1 of the first compressor 51 and the operating frequencies f2 of the second compressors 52 are the same, but also when the operating frequencies f1 of the first compressor 51 and the operating frequencies f2 of the second compressors 52 are close to each other to such an extent that resonance may occur.

[0100] FIG. 10 is a diagram showing an example of changes in the operating frequency f of each compressor 50 and an example of changes in the temperature in each room. FIG. 10 shows four graphs arranged vertically. The top graph in FIG. 10 is a graph showing an example of changes in the temperature Tr1 in the first chamber R1. The second graph from the top in FIG. 10 is a graph showing an example of changes in the temperature Tr2 in the second chamber R2. The second graph from the bottom in FIG. 10 is a graph showing an example of changes in the operating frequency f1 of the first compressor 51. The bottom graph in FIG. 10 is a graph showing an example of changes in the operating frequency f2 of the second compressor 52. In the top two graphs in FIG. 10, the horizontal axis represents time t, and the vertical axis represents temperature T. In the bottom two graphs in FIG. 10, the horizontal axis represents time t, and the vertical axis represents the operating frequency f.

[0101] FIG. 10 shows an example in which an operation start signal is input simultaneously to the first indoor unit 20a and the second indoor unit 20b at time t21, causing each indoor unit 20 to start cooling. At time t21, the temperature Tr1 in the first room R1 is temperature Td, and the temperature Tr2 in the second room R2 is temperature Te, which is higher than temperature Td. In the example of FIG. 10, the set temperature Ts1 of the first indoor unit 20a and the set temperature Ts2 of the second indoor unit 20b are the same. Therefore, at time t21, the difference between the set temperature Ts2 of the second indoor unit 20b and the temperature Tr2 in the second room R2 is greater than the difference between the set temperature Ts1 of the first indoor unit 20a and the temperature Tr1 in the first room R1. As a result, at time t21, each outdoor unit control unit 290 executes steps S13 and S16 described above, causing the second compressor 52 to be driven and the first compressor 51 to remain stopped.

[0102] 10, the operating frequency f2 of the second compressor 52 begins to rise from time t21, and reaches frequency ff based on the input command value at time t22. The start-up period RP of the second compressor 52 is from time t21 to time t22. When the second compressor 52 is driven, the second indoor unit 20b cools the second chamber R2, and the temperature Tr2 within the second chamber R2 drops.

[0103] As shown in the top two graphs of FIG. 10 , at time t23, which is later than time t22, the temperature Tr2 in the second room R2 becomes lower than the temperature Tc in the first room R1. That is, at time t23, the difference between the set temperature Ts2 of the second indoor unit 20b and the temperature Tr2 in the second room R2 is smaller than the difference between the set temperature Ts1 of the first indoor unit 20a and the temperature Tr1 in the first room R1. Therefore, the first outdoor unit control unit 291 executes steps S16 and S17 described above, and the first compressor 51 is driven. Note that, from time t21 to time t23, the first compressor 51 is not driven, but the blower 22 of the first indoor unit 20a is driven. Therefore, the air in the first room R1 is agitated by the air blown into the first room R1 from the first indoor unit 20a, and the temperature Tr1 in the first room R1 drops from temperature Td to temperature Tc, which is lower than temperature Td.

[0104] As shown in the second-lowest graph in Figure 10, the operating frequency f1 of the first compressor 51 begins to rise from time t23 and reaches frequency ff based on the input command value at time t24. The start-up period RP of the first compressor 51 is from time t23 to time t24. When the first compressor 51 is driven, the refrigerant 19 is sent to the first indoor unit 20a, which effectively cools the air in the first chamber R1. This causes the temperature Tr1 in the first chamber R1 to decrease at a steeper rate than when the blower 22 is only driven.

[0105] At time t24, when the operating frequency f1 of the first compressor 51 reaches frequency ff, the operating frequency f1 of the first compressor 51 and the operating frequency f2 of the second compressor 52 become the same. Therefore, each outdoor unit control unit 290 executes steps S18 and S19 described above to adjust the operating frequency f of each compressor 50. At time t24, the difference between the set temperature Ts2 of the second indoor unit 20b and the temperature Tr2 in the second room R2 is smaller than the difference between the set temperature Ts1 of the first indoor unit 20a and the temperature Tr1 in the first room R1. Therefore, the second outdoor unit control unit 292 lowers the operating frequency f2 of the second compressor 52, as in step S20. In the example of FIG. 10 , the second outdoor unit control unit 292 lowers the operating frequency f2 of the second compressor 52 to frequency fe, which is lower than frequency ff. The difference between the frequency ff and the frequency fe, that is, the reduction in the operating frequency f2, is preferably 3 Hz or more, as described above, and more preferably 5 Hz or more.

[0106] As shown in the top two graphs of Figure 10, after time t24, the operating frequency f2 of the second compressor 52 is lower than the operating frequency f1 of the first compressor 51, so the rate at which the temperature Tr2 in the second chamber R2 decreases is smaller than the rate at which the temperature Tr1 in the first chamber R1 decreases. At time t25, after time t24, the temperature Tr1 in the first chamber R1 reaches temperature Tb, which is lower than temperature Tc, and is lower than the temperature Tr2 in the second chamber R2. In other words, at time t25, the difference between the set temperature Ts2 of the second indoor unit 20b and the temperature Tr2 in the second chamber R2 is greater than the difference between the set temperature Ts1 of the first indoor unit 20a and the temperature Tr1 in the first chamber R1. Therefore, the second outdoor unit control unit 292 executes control similar to steps S18, S21, S22, and S23 described above, and the operating frequency f2 of the second compressor 52 is increased.

[0107] The operating frequency f2 of the second compressor 52 is increased from frequency fe to frequency ff between time t25 and time t26. At time t26, when the operating frequency f2 of the second compressor 52 reaches frequency ff, the operating frequency f1 of the first compressor 51 and the operating frequency f2 of the second compressor 52 become the same. Therefore, each outdoor unit control unit 290 executes steps S18 and S19 described above to adjust the operating frequency f of each compressor 50. At time t26, the difference between the set temperature Ts2 of the second indoor unit 20b and the temperature Tr2 in the second room R2 is greater than the difference between the set temperature Ts1 of the first indoor unit 20a and the temperature Tr1 in the first room R1. Therefore, the first outdoor unit control unit 291 executes steps S18, S19, and S20 to lower the operating frequency f1 of the first compressor 51. In the example of FIG. 10, the first outdoor unit control section 291 lowers the operating frequency f1 of the first compressor 51 to a frequency fe that is lower than the frequency ff.

[0108] At time t27, which is later than time t26, the difference between the temperature Tr2 in the second chamber R2 and the set temperature Ts2 of the second indoor unit 20b becomes less than a predetermined threshold, and the second outdoor unit control unit 292 decreases the operating frequency f2 of the second compressor 52 at a predetermined gradient and stops the second compressor 52.

[0109] At time t27, the temperature Tr1 in the first compartment R1 again becomes lower than the temperature Tr2 in the second compartment R2. This causes the first outdoor unit control unit 291 to execute step S23, and the operating frequency f1 of the first compressor 51 is increased from frequency fe to frequency ff. In the example of FIG. 10 , at time t28, which is after time t27, the operating frequency f1 of the first compressor 51 again becomes frequency ff. In the example of FIG. 10 , at time t28, the difference between the temperature Tr1 in the first compartment R1 and the set temperature Ts1 of the first indoor unit 20a becomes equal to or less than a predetermined threshold, and the first outdoor unit control unit 291 decreases the operating frequency f1 of the first compressor 51 at a predetermined gradient and stops the first compressor 51.

[0110] As in the first embodiment, each outdoor unit control unit 290 can operate each refrigerant circuit unit 80 in an operation mode different from the operation modes of the other refrigerant circuit units 80. In the second embodiment, each outdoor unit control unit 290 can determine the operation mode of each refrigerant circuit unit 80 based on information obtained from the other outdoor unit control units 290. For example, as in the first embodiment, each outdoor unit control unit 290 can determine whether to place each refrigerant circuit unit 80 in the defrosting operation mode based on temperature information of the heat exchanger 30 obtained from the temperature sensors 33 and 34. For example, the first outdoor unit control unit 291 can determine whether to place the first refrigerant circuit unit 81 in the defrosting operation mode based on temperature information of the first heat exchange unit 31 obtained from the temperature sensor 33 and information obtained from the second outdoor unit control unit 292. In this case, the information obtained from the second outdoor unit control unit 292 includes, for example, information regarding the operation mode of the second refrigerant circuit unit 82 and temperature information of the second heat exchange unit 32 obtained from the temperature sensor 34.

[0111] For example, if the first outdoor unit control unit 291 determines that the temperature of the heat exchanger 30 is lower than a predetermined third threshold value and higher than a predetermined fourth threshold value, and if the first outdoor unit control unit 291 determines that the temperature of the first heat exchange unit 31 is lower than the temperature of the second heat exchange unit 32, the first outdoor unit control unit 291 sets the operation mode of the first refrigerant circuit unit 81 to the defrosting operation mode. The fourth threshold value is a value lower than the third threshold value. If the first outdoor unit control unit 291 determines that the temperature of the heat exchanger 30 is lower than the third threshold value and higher than the fourth threshold value, and if the first outdoor unit control unit 291 determines that the temperature of the first heat exchange unit 31 is higher than the temperature of the second heat exchange unit 32, the first outdoor unit control unit 291 does not set the operation mode of the first refrigerant circuit unit 81 to the defrosting operation mode. In this case, the second outdoor unit control unit 292 sets the operation mode of the second refrigerant circuit unit 82 to the defrosting operation mode by making the same determination as the first outdoor unit control unit 291. Note that when the first outdoor unit control unit 291 determines that the temperature of the heat exchanger 30 is lower than the third threshold value and higher than the fourth threshold value, and when it determines that the temperature of the first heat exchange unit 31 is higher than the temperature of the second heat exchange unit 32, if the operation mode of the second refrigerant circuit unit 82 is not the defrosting operation mode for some reason, the first outdoor unit control unit 291 may set the operation mode of the first refrigerant circuit unit 81 to the defrosting operation mode. When the first outdoor unit control unit 291 determines that the temperature of the heat exchanger 30 is lower than the third threshold value and lower than the fourth threshold value, the second outdoor unit control unit 292 also makes a determination similar to that of the first outdoor unit control unit 291, and sets the operation mode of the second refrigerant circuit unit 82 to the defrosting operation mode. For example, when each outdoor unit control unit 290 determines not to set each refrigerant circuit unit 80 to the defrosting operation mode, if another refrigerant circuit unit 80 is in the defrosting operation mode, it stops the operation of that refrigerant circuit unit 80. The control regarding the defrosting operation mode by the first outdoor unit control unit 291 described above also applies to the second outdoor unit control unit 292.

[0112] In the second embodiment, the power supply control unit 293 supplies power to each of the multiple outdoor unit control units 290, i.e., the first outdoor unit control unit 291 and the second outdoor unit control unit 292. As in the first embodiment, the power supply control unit 293 also supplies power to each of the multiple compressors 50 and the multiple indoor units 20. The power supply control unit 293 is capable of supplying power to some of the outdoor unit control units 290, some of the compressors 50, and some of the indoor units 20, while stopping the supply of power to other outdoor unit control units 290, other compressors 50, and other indoor units 20. Specifically, for example, it is capable of supplying power to the first outdoor unit control unit 291, the first compressor 51, and the first indoor unit 20a, while stopping the supply of power to the second outdoor unit control unit 292, the second compressor 52, and the second indoor unit 20b.

[0113] If the power supply control unit 293 determines, based on signals from each outdoor unit control unit 290, that there is a refrigerant circuit unit 80 that has been stopped operating for a relatively long period of time, it stops supplying power to the indoor unit 20 connected to that refrigerant circuit unit 80, the compressor 50 provided in that refrigerant circuit unit 80, and the outdoor unit control unit 290 that controls that refrigerant circuit unit 80.

[0114] The outdoor unit control unit 290, to which the supply of power from the power supply control unit 293 has been stopped, enters the second standby mode. The second standby mode is a mode in which the outdoor unit control unit 290 can only accept start-up commands from the indoor unit control unit 25, using power stored in a capacitor (not shown) mounted in the outdoor unit control unit 290. When the outdoor unit control unit 290 enters the second standby mode, power is not supplied to the indoor units 20 connected to the refrigerant circuit unit 80 controlled by the outdoor unit control unit 290, and the indoor units 20 enter the first standby mode described in embodiment 1. When an operation command is input to the indoor unit 20 that has entered the first standby mode, a start-up command is sent from the indoor unit control unit 25 to the outdoor unit control unit 290 that is in the second standby mode, the outdoor unit control unit 290 enters normal operation mode, and a signal is sent from the outdoor unit control unit 290 to the power supply control unit 293, and the power supply from the power supply control unit 293 to the indoor unit 20, the outdoor unit control unit 290, and the compressor 50 controlled by the outdoor unit control unit 290 is resumed.

[0115] According to the second embodiment, the control device 290a has multiple outdoor unit control units 290, one for each of the multiple refrigerant circuit units 80. The multiple outdoor unit control units 290 are capable of independently controlling the multiple refrigerant circuit units 80. Each outdoor unit control unit 290 is capable of controlling each refrigerant circuit unit 80 based on information about the other refrigerant circuit units 80 obtained from the other outdoor unit control units 290. This makes it possible to suitably adjust the operation of the multiple refrigerant circuit units 80 in accordance with the operating conditions of the other refrigerant circuit units 80. This makes it easy to operate the multiple compressors 50 in a way that suppresses resonance between the multiple compressors 50. This makes it possible to suppress abnormal noise from the outdoor unit 210.

[0116] Furthermore, according to the second embodiment, the outdoor unit 210 includes a power supply control unit 293 that supplies power to each of the multiple outdoor unit control units 290 and the multiple compressors 50. The power supply control unit 293 is capable of supplying power to some of the outdoor unit control units 290 and some of the compressors 50, while stopping the supply of power to other outdoor unit control units 290 and other compressors 50. Therefore, when it is not necessary to operate some of the refrigerant circuit units 80, the supply of power to the outdoor unit control units 290 that control those refrigerant circuit units 80 can be stopped, thereby reducing the power consumption of the air conditioner 200.

[0117] Furthermore, according to the second embodiment, the control device 290a controls each compressor 50 so that the start timing of each compressor 50 is staggered. This prevents multiple compressors 50 from starting to operate simultaneously. Here, during the start-up period RP when the compressors 50 start to operate, the power required by the compressors 50 is greater than when the compressors 50 are operating steadily. Therefore, if multiple compressors 50 start to operate simultaneously, the power required by the air conditioner 200 may temporarily increase, potentially tripping the breaker of the external power supply 94. In contrast, according to the second embodiment, the start-up periods RP during which the operating frequencies f increase are prevented from overlapping, thereby further preventing the operating frequencies f of the multiple compressors 50 from becoming the same. This further prevents resonance between the multiple compressors 50. This further prevents abnormal noise from the outdoor unit 210.

[0118] Furthermore, according to the second embodiment, the control device 290a controls each compressor 50 so that the operating frequencies f of the compressors 50 are different from one another. This makes it possible to more effectively prevent the operating frequencies f of the multiple compressors 50 from becoming the same. This makes it possible to more effectively prevent resonance between the multiple compressors 50. This makes it possible to more effectively prevent abnormal noise from being generated from the outdoor unit 210.

[0119] Furthermore, according to the second embodiment, as explained in steps S11 to S23 above, the control device 290a determines the magnitude of the air conditioning load in each indoor unit 20 based on the difference between the set temperature of each indoor unit 20 and the temperature in each room, and prioritizes driving the compressor 50 of the refrigerant circuit section 80 connected to the indoor unit 20 with the greater air conditioning load. This makes it possible to prevent the drive of each compressor 50 from starting at the same time and to prevent the operating frequencies f of each compressor 50 from becoming the same, while preventing the comfort in each room from being impaired. Note that "driving a certain compressor 50 with priority" includes, for example, starting the drive of a certain compressor 50 earlier in time than the drive of other compressors 50, and setting the operating frequency f of a certain compressor 50 higher than the operating frequency f of the other compressors 50.

[0120] The method of controlling the multiple compressors 50 by the multiple outdoor unit control units 290 described in embodiment 2 using Figures 8 to 10 may be performed by a single outdoor unit control unit 290, as in embodiment 1.

[0121] Embodiment 3. Fig. 11 is a schematic diagram showing the general configuration of an air conditioner 300 in embodiment 3. In the following description, the same components as those in the above-described embodiments may be denoted by the same reference numerals as appropriate, and the description thereof may be omitted.

[0122] As shown in FIG. 11 , in the outdoor unit 310 of the air conditioner 300 of the third embodiment, the capacity of the second compressor 352 is different from that of the first compressor 51. The rated output of the second compressor 352 is greater than the rated output of the first compressor 51. In other words, in the third embodiment, the rated outputs of the multiple compressors 50 are different from one another. The difference between the rated outputs of the first compressor 51 and the second compressor 352 is preferably such that, when each compressor 50 pumps the same amount of refrigerant 19 per unit time, the difference between the operating frequency f1 of the first compressor 51 and the operating frequency f2 of the second compressor 352 is 3 Hz or more, and more preferably 5 Hz or more. The size of the housing of the second compressor 352 is larger than that of the first compressor 51. The other configuration of the second compressor 352 is similar to that of the second compressor 52 of the first embodiment.

[0123] In the outdoor unit 310, the amounts of refrigerant 19 sealed in the multiple refrigerant circuit sections 80 are different from one another, as in the first embodiment. The amount of refrigerant 19 sealed in the first refrigerant circuit section 81 is refrigerant amount α. The amount of refrigerant 19 sealed in the second refrigerant circuit section 82 is refrigerant amount β, which is greater than refrigerant amount α. As in the second embodiment, the control device 290a has multiple outdoor unit control sections 290. The control device 290a has a first outdoor unit control section 291 and a second outdoor unit control section 292. In the third embodiment, each outdoor unit control section 290 performs the same control as each outdoor unit control section 290 described in the second embodiment. The other configurations of the air conditioner 300 are the same as the other configurations of the air conditioner 200 in the second embodiment.

[0124] According to the third embodiment, the amounts of refrigerant 19 sealed in the multiple refrigerant circuit sections 80 are different from one another, and each outdoor unit control section 290 can control each refrigerant circuit section 80 based on information about the other refrigerant circuit sections 80 obtained from the other outdoor unit control sections 290. Therefore, in the same manner as described in the first and second embodiments, it is possible to preferably prevent the operating frequencies f of the multiple compressors 50 from becoming the same. This makes it possible to more preferably prevent resonance between the multiple compressors 50 and more preferably prevent abnormal noise from being generated from the outdoor unit 310.

[0125] Furthermore, as described in the first embodiment, when the amount of refrigerant 19 pumped per unit time is the same, the greater the amount of refrigerant 19 sealed in the refrigerant circuit section 80, the lower the operating frequency f of the compressor 50 provided in that refrigerant circuit section 80. In this case, the start-up period RP from when the compressor 50 starts to operate until the operating frequency f of the compressor 50 reaches a steady-state value based on the command value becomes shorter. Therefore, when the amounts of refrigerant 19 sealed in the refrigerant circuit sections 80 are different from one another, staggering the start-up periods RP of the compressors 50 can shorten the time from when the compressor 50 in the refrigerant circuit section 80 with a relatively large amount of refrigerant 19 starts to operate until the compressor 50 in the refrigerant circuit section 80 with a relatively small amount of refrigerant 19 starts to operate.

[0126] Furthermore, according to the third embodiment, the rated outputs of the multiple compressors 50 are different from one another. Even when the multiple compressors 50 with different rated outputs are driven at the same operating frequency f, the amount of refrigerant 19 that can be pumped per unit time is different from one another. Therefore, when pumping the same amount of refrigerant 19, the operating frequencies f of the multiple compressors 50 are different from one another. This makes it easier to shift the operating frequencies f of the multiple compressors 50 from one another, thereby more effectively preventing resonance between the multiple compressors 50. Therefore, noise from the outdoor unit 310 can be more effectively prevented. Furthermore, by providing compressors 50 of different sizes in each refrigerant circuit section 80 according to the amount of refrigerant 19 sealed in each refrigerant circuit section 80, the size of each compressor 50 can be minimized within the necessary range. This facilitates minimizing the space required for installing the multiple compressors 50 within the outdoor unit 310.

[0127] In the third embodiment, the rated outputs of the plurality of compressors 50 may be the same. In the third embodiment, the plurality of compressors 50 may be compressors of the same model.

[0128] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the configurations of the above-described embodiments, and the following configurations and methods may also be adopted.

[0129] The number of refrigerant circuit sections provided in the outdoor unit is not particularly limited as long as it is two or more. When the amounts of refrigerant sealed in the multiple refrigerant circuit sections are different from one another, the difference in the amounts of refrigerant sealed in the multiple refrigerant circuit sections is not particularly limited. The types of refrigerant sealed in the refrigerant circuit sections may be the same or different from one another. The method of controlling the refrigerant circuit sections by the outdoor unit control section is not limited to the control methods in the above-described embodiments, and is not particularly limited.

[0130] At least some of the functions of the control units described in the above-described embodiments are realized, for example, by a processor such as a CPU executing a program, i.e., software, stored in a storage unit (not shown). Each control unit includes each control unit in the outdoor unit control device, i.e., an outdoor unit control unit and a power supply control unit, and an indoor unit control unit. Note that at least some of the functions of each control unit may be realized by hardware including circuit units such as an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), and a GPU (Graphics Processing Unit), or may be realized by a combination of software and hardware. The storage unit (not shown) is realized by a storage medium such as a RAM (Random Access Memory), a ROM (Read Only Memory), a HDD (Hard Disk Drive), a flash memory, etc. The storage unit (not shown) may be provided in the air conditioner, or may be provided external to the air conditioner and be capable of communicating with the air conditioner via wired or wireless communication.

[0131] The configurations and methods described in this specification can be combined as appropriate within the scope of not contradicting each other.

[0132] 10, 210, 310... outdoor unit, 19... refrigerant, 20... indoor unit, 50... compressor, 80... refrigerant circuit section, 83... connection section, 83a, 83b... connection piping, 88a, 88b... refrigerant piping, 90, 290... outdoor unit control section, 90a, 290a... control device, 93, 293... power supply control section, 100, 200, 300... air conditioner, 291... first outdoor unit control section (outdoor unit control section), 292... second outdoor unit control section (outdoor unit control section), f, f1, f2... operating frequency

Claims

1. An outdoor unit of an air conditioner to which a plurality of indoor units are connected, a plurality of refrigerant circuit sections each connected to at least one of the indoor units; a plurality of compressors respectively provided in the plurality of refrigerant circuit sections; a control device that controls the plurality of refrigerant circuit units; Equipped with the control device has a plurality of outdoor unit control units provided for the plurality of refrigerant circuit units, the plurality of outdoor unit control units are capable of independently controlling the plurality of refrigerant circuit units, each outdoor unit control unit is capable of controlling each refrigerant circuit unit based on information relating to the other refrigerant circuit units obtained from the other outdoor unit control units; the plurality of refrigerant circuit units include a first refrigerant circuit unit and a second refrigerant circuit unit, The plurality of compressors include: a first compressor provided in the first refrigerant circuit section; a second compressor provided in the second refrigerant circuit section; Including, The plurality of indoor units include: a first indoor unit connected to the first refrigerant circuit section; a second indoor unit connected to the second refrigerant circuit section; Including, The plurality of outdoor unit control units include: a first outdoor unit control unit that controls the first refrigerant circuit unit and the first indoor unit; a second outdoor unit control unit that controls the second refrigerant circuit unit and the second indoor unit; Including, When an operation start signal for starting operation of the first indoor unit and the second indoor unit is input, each of the first outdoor unit control unit and the second outdoor unit control unit: Based on information about the other indoor unit obtained from the other outdoor unit control unit, the set temperature of the other indoor unit and the temperature of the room in which the other indoor unit is located are obtained; When it is determined that the difference between the set temperature of the other indoor unit and the temperature in the room in which the other indoor unit is located is smaller than the difference between the set temperature of the indoor unit that it controls and the temperature in the room in which the indoor unit that it controls is located, it drives the compressor that is provided in the refrigerant circuit unit that it controls, the outdoor unit controls the first compressor and the second compressor such that a timing at which the first compressor starts to be driven and a timing at which the second compressor starts to be driven are shifted from each other.

2. a power supply control unit that supplies power to each of the outdoor unit control units and the compressors; The outdoor unit according to claim 1 , wherein the power supply control unit is capable of supplying power to some of the outdoor unit control units and some of the compressors, while stopping the supply of power to other outdoor unit control units and other compressors.

3. The outdoor unit according to claim 1 , wherein the control device controls the compressors so that the operating frequencies of the compressors are different from each other.

4. A plurality of operation modes of the plurality of refrigerant circuit units are provided, The outdoor unit according to claim 1 , wherein the control device is capable of operating each of the refrigerant circuit sections in the operation mode different from the operation modes of the other refrigerant circuit sections.

5. The outdoor unit according to claim 4 , wherein the control device is capable of determining the operation mode of each of the refrigerant circuit units based on information relating to the other refrigerant circuit units.

6. The outdoor unit according to claim 1 , wherein the control device is capable of continuing operation of the other refrigerant circuit units when operation of one of the refrigerant circuit units abnormally stops.

7. The outdoor unit according to claim 6, wherein the control device notifies the user that an abnormality has occurred in a portion of the refrigerant circuit section when operation of the portion of the refrigerant circuit section has abnormally stopped.

8. Each of the plurality of refrigerant circuit units has a connection unit consisting of two connection pipes, Two refrigerant pipes extending from one of the indoor units can be connected to the two connection pipes, respectively; The outdoor unit according to claim 1 , wherein the number of the connection parts included in each of the refrigerant circuit parts is the same as each other.

9. The outdoor unit according to claim 1 , wherein the plurality of compressors have different rated outputs.

10. An outdoor unit as described in claim 1, wherein the amounts of refrigerant sealed in the multiple refrigerant circuit sections are different from each other.

11. An outdoor unit according to any one of claims 1 to 10; the plurality of indoor units connected to the outdoor unit; An air conditioner comprising: