Air conditioner performing oil collection operation and control method thereof

Abstract

An air conditioner is provided. The air conditioner may comprise: a plurality of indoor units; an outdoor unit including a condenser and a compressor; a memory for storing at least one instruction; and at least one processor. Each of the plurality of indoor units may include an expansion valve, an evaporator, and a detection sensor. The at least one processor, when the at least one instruction is executed, may perform an oil collection operation of collecting oil to the compressor, detect, when there is an indoor unit in an off state in which power is turned off among the plurality of indoor units, an occupant in a space of concern by using a detection sensor of the indoor unit in the off state while performing the oil collection operation, and control an open state of an expansion valve of the indoor unit in the off state on the basis of an occupant detection result of the indoor unit in the off state while performing the oil collection operation.

Description

Air conditioner performing oil recovery operation and control method thereof

[0001] Embodiments of the present disclosure relate to an air conditioner performing oil recovery operation, a method for controlling the air conditioner, and a computer-readable recording medium having recorded thereon a program for performing the air conditioner control method on a computer.

[0002] An air conditioner can regulate air conditions, such as temperature, humidity, and cleanliness. Typically, an air conditioner includes a heat pump device consisting of a compressor, a condenser, an expansion device, and an evaporator, and can drive a refrigerant cycle by controlling the heat pump device to compress, condense, expand, and evaporate a refrigerant.

[0003] A heat pump compressor compresses refrigerant. Heat pump devices use oil for lubrication to protect the compressor from mechanical friction. The oil inside the compressor circulates through the refrigerant cycle within the heat pump device along with the refrigerant discharged from the compressor. As the refrigerant is compressed within the compressor, the oil inside the compressor mixes with the refrigerant and is discharged. However, if the refrigerant circulates through the heat pump piping while still mixed with oil, it can interfere with refrigerant circulation. Furthermore, the discharge of oil from the compressor reduces the amount of oil in the compressor, potentially degrading compressor performance. To prevent these adverse effects, air conditioners can periodically perform oil recovery operations to return oil to the compressor.

[0004] According to one aspect of one embodiment of the present disclosure, an air conditioner is provided. The air conditioner may include a plurality of indoor units, an outdoor unit including a condenser and a compressor, a memory storing at least one instruction, and at least one processor. Each of the plurality of indoor units may include an expansion valve, an evaporator, and a detection sensor. The at least one processor may execute at least one instruction to perform an oil recovery operation for recovering oil using a compressor, and while performing the oil recovery operation, if there is an indoor unit that is turned off among the plurality of indoor units, detect an occupant of a target space using a detection sensor of the indoor unit in the off state, and while performing the oil recovery operation, control an open state of an expansion valve of the indoor unit in the off state based on a result of detecting an occupant of the indoor unit in the off state.

[0005] In addition, according to one aspect of one embodiment of the present disclosure, a method for controlling an air conditioner is provided. The air conditioner may include a plurality of indoor units and an outdoor unit, the outdoor unit may include a condenser and a compressor, and each of the plurality of indoor units may include an expansion valve, an evaporator, and a detection sensor. The method for controlling the air conditioner may include a step of performing an oil recovery operation for recovering oil by a compressor, a step of detecting an occupant of a target space using a detection sensor of an indoor unit in the off state when an indoor unit in an off state with its power turned off exists among the plurality of indoor units during the oil recovery operation, and a step of controlling an open state of an expansion valve of the indoor unit in the off state based on a result of detecting an occupant of the indoor unit in the off state during the oil recovery operation.

[0006] In addition, according to one aspect of one embodiment of the present disclosure, a computer-readable recording medium having recorded thereon a program for performing an air conditioner control method according to one embodiment of the present disclosure on a computer is provided.

[0007] FIG. 1 is a drawing showing the structure and operation of an air conditioner according to one embodiment of the present disclosure.

[0008] FIG. 2 is a drawing showing the structure of an air conditioner according to one embodiment of the present disclosure.

[0009] FIG. 3 is a flowchart illustrating an air conditioner control method according to one embodiment of the present disclosure.

[0010] FIG. 4 is a drawing for explaining the operation of oil recovery operation of an air conditioner according to one embodiment of the present disclosure.

[0011] FIG. 5 is a flowchart illustrating a process of performing oil recovery operation according to one embodiment of the present disclosure.

[0012] FIG. 6 is a flowchart illustrating an oil recovery operation when an occupant is detected in a target space of an indoor unit in an off state according to one embodiment of the present disclosure.

[0013] FIG. 7 is a flowchart illustrating a process for determining performance conditions of an oil recovery operation according to one embodiment of the present disclosure.

[0014] FIG. 8 is a block diagram showing the structure of an air conditioner according to one embodiment of the present disclosure.

[0015] FIG. 9 is a diagram illustrating an air conditioner, an external device, and a server according to one embodiment of the present disclosure.

[0016] FIG. 10 is a diagram illustrating an operation of an air conditioner outputting a notification during oil recovery operation according to one embodiment of the present disclosure.

[0017] FIG. 11 is a flowchart illustrating a process of performing oil recovery operation according to one embodiment of the present disclosure.

[0018] FIG. 12 is a flowchart illustrating a process for performing oil recovery operation according to one embodiment of the present disclosure.

[0019] It should be understood that the various embodiments and terms used in this document are not intended to limit the technical features described in this document to specific embodiments, but rather to encompass various modifications, equivalents, or alternatives of the embodiments.

[0020] In connection with the description of the drawings, similar reference numerals may be used for similar or related components.

[0021] The singular form of a noun corresponding to an item may include one or more of said items, unless the relevant context clearly indicates otherwise.

[0022] Unless the context clearly dictates otherwise, the singular forms "a," "an," and "the" are to be understood to include plural referents. Thus, for example, the description "a constituent surface" may also include reference to one or more of such surfaces.

[0023] In this document, each of the phrases "A or B", "at least one of A and B", "at least one of A or B", "A, B, or C", "at least one of A, B, and C", and "at least one of A, B, or C" may include any one of the items listed together in that phrase, or all possible combinations thereof.

[0024] The term “and / or” includes any combination of a plurality of related described elements or any one of a plurality of related described elements.

[0025] Terms such as "first," "second," or "first" or "second" may be used simply to distinguish one component from another and do not qualify the components in any other respect (e.g., importance or order).

[0026] When a component (e.g., a first component) is referred to as being "coupled" or "connected" to another component (e.g., a second component), with or without the terms "functionally" or "communicatively," it means that the component can be connected to the other component directly (e.g., wired), wirelessly, or through a third component.

[0027] The terms “include” or “have” are intended to specify the presence of a feature, number, step, operation, component, part or combination thereof described in this document, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0028] When a component is said to be “connected,” “coupled,” “supported,” or “in contact with” another component, this includes not only cases where the components are directly connected, coupled, supported, or in contact, but also cases where the components are indirectly connected, coupled, supported, or in contact through a third component.

[0029] When we say that a component is “on” another component, this includes not only cases where the component is in contact with the other component, but also cases where there is another component between the two components.

[0030] It should be understood that the blocks and combinations of flowcharts in each flowchart can be executed by one or more computer programs containing computer-executable instructions. The one or more computer programs may be stored entirely in a single memory, or may be stored in separate portions across multiple different memories.

[0031] All functions or operations described in this document may be performed by a single processor or a combination of processors. A single processor or a combination of processors is a circuitry that performs processing, and may include circuitry such as an Application Processor (AP), a Communication Processor (CP), a Graphical Processing Unit (GPU), a Neural Processing Unit (NPU), a Microprocessor Unit (MPU), a System on Chip (SoC), or an Integrated Chip (IC).

[0032] An air conditioner according to one embodiment of the present disclosure is a device that performs functions such as air purification, ventilation, humidity control, cooling, or heating in an air-conditioned space (hereinafter referred to as “indoor”), and means a device equipped with at least one of these functions.

[0033] According to one embodiment of the present disclosure, an air conditioner may include a heat pump device to perform a cooling function or a heating function. The heat pump device may include a refrigeration cycle in which a refrigerant circulates along a compressor, a first heat exchanger, an expansion device, and a second heat exchanger. All components of the heat pump device may be housed in a single housing forming the exterior of the air conditioner, such as a window air conditioner or a portable air conditioner. On the other hand, some components of the heat pump device may be housed separately in multiple housings forming a single air conditioner, such as a wall-mounted air conditioner, a standing air conditioner, a system air conditioner, etc.

[0034] An air conditioner including a plurality of housings may include at least one outdoor unit installed outdoors and at least one indoor unit installed indoors. For example, the air conditioner may be configured such that one outdoor unit and one indoor unit are connected via a refrigerant pipe. For example, the air conditioner may be configured such that one outdoor unit is connected to two or more indoor units via refrigerant pipes. For example, the air conditioner may be configured such that two or more outdoor units and two or more indoor units are connected via a plurality of refrigerant pipes.

[0035] The outdoor unit can be electrically connected to the indoor unit. For example, information (or commands) for controlling the air conditioner can be input through an input interface provided on the outdoor or indoor unit, and the outdoor and indoor units can operate simultaneously or sequentially in response to user input.

[0036] The air conditioner may include an outdoor heat exchanger provided in the outdoor unit, an indoor heat exchanger provided in the indoor unit, and a refrigerant pipe connecting the outdoor heat exchanger and the indoor heat exchanger.

[0037] An outdoor heat exchanger can utilize a phase change (e.g., evaporation or condensation) of the refrigerant to exchange heat between the refrigerant and the outdoor air. For example, while the refrigerant condenses in the outdoor heat exchanger, the refrigerant releases heat to the outdoor air, and while the refrigerant flowing in the outdoor heat exchanger evaporates, the refrigerant absorbs heat from the outdoor air.

[0038] Indoor units are installed indoors. For example, indoor units can be categorized into ceiling-mounted, stand-alone, and wall-mounted types depending on their placement. For example, ceiling-mounted indoor units can be categorized into four-way, one-way, and duct-type indoor units depending on how air is discharged.

[0039] Similarly, an indoor heat exchanger can utilize the phase change of the refrigerant (e.g., evaporation or condensation) to exchange heat between the refrigerant and indoor air. For example, while the refrigerant evaporates in the indoor unit, the refrigerant can absorb heat from the indoor air, and by blowing the cooled indoor air through the cooled indoor heat exchanger, the indoor space can be cooled. Furthermore, while the refrigerant condenses in the indoor heat exchanger, the refrigerant can release heat to the indoor air, and by blowing the heated indoor air through the high-temperature indoor heat exchanger, the indoor space can be heated.

[0040] That is, the air conditioner performs a cooling or heating function through a phase change process of the refrigerant circulating between the outdoor heat exchanger and the indoor heat exchanger. To circulate the refrigerant, the air conditioner may include a compressor that compresses the refrigerant. The compressor can suck in refrigerant gas through the suction port and compress the refrigerant gas. The compressor can discharge the high-temperature and high-pressure refrigerant gas through the discharge port. The compressor may be placed inside the outdoor unit.

[0041] The refrigerant may circulate through the refrigerant pipes in the order of a compressor, an outdoor heat exchanger, an expansion device, and an indoor heat exchanger, or in the order of a compressor, an indoor heat exchanger, an expansion device, and an outdoor heat exchanger.

[0042] For example, if an air conditioner has one outdoor unit and one indoor unit directly connected through a refrigerant pipe, the refrigerant may be arranged to circulate between one outdoor unit and one indoor unit through the refrigerant pipe.

[0043] For example, in an air conditioner, if one outdoor unit is connected to two or more indoor units via refrigerant pipes, the refrigerant can flow to multiple indoor units via refrigerant pipes branching from the outdoor unit. The refrigerant discharged from the multiple indoor units can be combined and circulated to the outdoor unit. For example, multiple indoor units can be directly connected in parallel to a single outdoor unit via separate refrigerant pipes.

[0044] Multiple indoor units can operate independently, each according to a user-defined operating mode. That is, some indoor units can operate in cooling mode, while others operate in heating mode. In this case, the refrigerant can be selectively introduced into each indoor unit at either high or low pressure along a designated circulation path via a flow-through valve, described later, and then discharged to the outdoor unit for circulation.

[0045] For example, when an air conditioner has two or more outdoor units and two or more indoor units connected through multiple refrigerant pipes, the refrigerant discharged from the multiple outdoor units may join and flow through a single refrigerant pipe, then branch off again at some point and flow into multiple indoor units.

[0046] Multiple outdoor units may be operated, or at least some may not be operated, depending on the operating load of the multiple indoor units. In this case, the refrigerant may be introduced into the outdoor unit, which is selectively operated, through a flow switching valve and circulated there. The air conditioner may include an expansion device to reduce the pressure of the refrigerant flowing into the heat exchanger. For example, the expansion device may be located within the indoor unit, the outdoor unit, or both.

[0047] An expansion device can, for example, utilize a throttling effect to lower the temperature and pressure of the refrigerant. The expansion device may include an orifice capable of reducing the cross-sectional area of ​​the flow path. Refrigerant passing through the orifice may experience a decrease in temperature and pressure.

[0048] The expansion device may be implemented as, for example, an electronic expansion valve capable of controlling the opening ratio (the ratio of the cross-sectional area of ​​the valve's flow path when partially open to the cross-sectional area of ​​the valve's flow path when fully open). Depending on the opening ratio of the electronic expansion valve, the amount of refrigerant passing through the expansion device can be controlled.

[0049] The air conditioner may further include a flow diverter valve positioned on the refrigerant circulation path. The flow diverter valve may include, for example, a four-way valve. The flow diverter valve may determine the refrigerant circulation path depending on the operating mode of the indoor unit (e.g., cooling operation or heating operation). The flow diverter valve may be connected to the discharge port of the compressor.

[0050] The air conditioner may include an accumulator. The accumulator may be connected to the suction port of the compressor. The accumulator may receive low-temperature, low-pressure refrigerant vaporized in an indoor heat exchanger or an outdoor heat exchanger.

[0051] The accumulator can separate the refrigerant liquid from the refrigerant gas when a refrigerant mixture of refrigerant liquid and refrigerant gas is introduced, and provide the refrigerant gas from which the refrigerant liquid has been separated to the compressor.

[0052] An outdoor fan may be installed adjacent to the outdoor heat exchanger. The outdoor fan may blow outdoor air to the outdoor heat exchanger to promote heat exchange between the refrigerant and the outdoor air.

[0053] The outdoor unit of the air conditioner may include at least one sensor. For example, the sensor of the outdoor unit may be provided as an environmental sensor. The outdoor unit sensor may be positioned at any location inside or outside the outdoor unit. For example, the outdoor unit sensor may include a temperature sensor for detecting the air temperature around the outdoor unit, a humidity sensor for detecting the air humidity around the outdoor unit, a refrigerant temperature sensor for detecting the refrigerant temperature of a refrigerant pipe passing through the outdoor unit, or a refrigerant pressure sensor for detecting the refrigerant pressure of a refrigerant pipe passing through the outdoor unit.

[0054] An outdoor unit of an air conditioner may include an outdoor unit communication unit. The outdoor unit communication unit may be configured to receive a control signal from a control unit of an indoor unit of the air conditioner, which will be described later. The outdoor unit may control the operation of a compressor, an outdoor heat exchanger, an expansion device, a flow switching valve, an accumulator, or an outdoor fan based on the control signal received through the outdoor unit communication unit. The outdoor unit may transmit a sensing value detected by an outdoor unit sensor to the control unit of the indoor unit through the outdoor unit communication unit.

[0055] The indoor unit of the air conditioner may include a housing, a blower for circulating air into or out of the housing, and an indoor heat exchanger for exchanging heat with air flowing into the interior of the housing.

[0056] The housing may include an intake port through which indoor air may be drawn into the interior of the housing.

[0057] The indoor unit of the air conditioner may include a filter that is provided to filter foreign substances in the air that flows into the housing through the intake port.

[0058] The housing may include an exhaust port. Air flowing within the housing may be discharged to the exterior of the housing through the exhaust port.

[0059] The housing of the indoor unit may be provided with an airflow guide that guides the direction of air discharged through the exhaust port. For example, the airflow guide may include blades positioned above the exhaust port. For example, the airflow guide may include an auxiliary fan for controlling the exhaust airflow. However, the airflow guide is not limited thereto and may be omitted.

[0060] An indoor heat exchanger and a blower may be provided inside the housing of the indoor unit, which are arranged on a path connecting the intake and exhaust ports.

[0061] Blowers may include indoor fans and fan motors. For example, indoor fans may include axial fans, diffusion fans, crossflow fans, and centrifugal fans.

[0062] An indoor heat exchanger may be positioned between the blower and the exhaust, or between the intake and the blower. The indoor heat exchanger may absorb heat from air drawn in through the intake, or transfer heat to the air drawn in through the intake. The indoor heat exchanger may include heat exchange tubes through which refrigerant flows, and heat exchange fins in contact with the heat exchange tubes to increase the heat transfer surface area.

[0063] The indoor unit of the air conditioner may include a drain tray positioned below the indoor heat exchanger to collect condensate generated in the indoor heat exchanger. The condensate collected in the drain tray may be drained to the outside through a drain hose. The drain tray may be provided to support the indoor heat exchanger.

[0064] The indoor unit of the air conditioner may include an input interface. The input interface may include any type of user input means, including buttons, switches, a touch screen, and / or a touch pad. The user can directly input setting data (e.g., desired indoor temperature, operating mode settings for cooling / heating / dehumidification / air purification, outlet selection settings, and / or air flow settings) through the input interface.

[0065] The input interface may also be connected to an external input device. For example, the input interface may be electrically connected to a wired remote controller. The wired remote controller may be installed at a specific location in an indoor space (e.g., a portion of a wall). A user may input configuration data regarding the operation of the air conditioner by operating the wired remote controller. Electrical signals corresponding to the configuration data obtained through the wired remote controller may be transmitted to the input interface. In addition, the input interface may include an infrared sensor. A user may remotely input configuration data regarding the operation of the air conditioner using the wireless remote controller. The configuration data input through the wireless remote controller may be transmitted to the input interface as an infrared signal.

[0066] Additionally, the input interface may include a microphone. A user's voice command may be acquired through the microphone. The microphone may convert the user's voice command into an electrical signal and transmit the converted electrical signal to an indoor unit control unit. The indoor unit control unit may control components of the air conditioner to execute a function corresponding to the user's voice command. Setting data acquired through the input interface (e.g., desired indoor temperature, operation mode settings for cooling / heating / dehumidification / air purification, outlet selection settings, and / or air volume settings) may be transmitted to the indoor unit control unit, which will be described later. In one example, the setting data acquired through the input interface may be transmitted externally, i.e., to an outdoor unit or a server, through an indoor unit communication unit, which will be described later.

[0067] The indoor unit of the air conditioner may include a power module. The power module may be connected to an external power source to supply power to components of the indoor unit.

[0068] An indoor unit of an air conditioner may include an indoor unit sensor. The indoor unit sensor may be an environmental sensor positioned in a space inside or outside the housing. For example, the indoor unit sensor may include one or more temperature sensors and / or humidity sensors positioned in a predetermined space inside or outside the housing of the indoor unit. For example, the indoor unit sensor may include a refrigerant temperature sensor for detecting a refrigerant temperature of a refrigerant pipe passing through the indoor unit. For example, the indoor unit sensor may include respective refrigerant temperature sensors for detecting the inlet, middle, and / or outlet temperatures of the refrigerant pipe passing through the indoor heat exchanger.

[0069] For example, each environmental information detected by an indoor unit sensor can be transmitted to the indoor unit control unit described later or transmitted externally through the indoor unit communication unit described later.

[0070] The indoor unit of the air conditioner may include an indoor unit communication unit. The indoor unit communication unit may include at least one of a short-range communication module and a long-range communication module. The indoor unit communication unit may include at least one antenna for wireless communication with other devices. The outdoor unit may include an outdoor unit communication unit. The outdoor unit communication unit may also include at least one of a short-range communication module and a long-range communication module.

[0071] The short-range wireless communication module may include, but is not limited to, a Bluetooth communication module, a BLE (Bluetooth Low Energy) communication module, a near field communication module, a WLAN (Wi-Fi) communication module, a Zigbee communication module, an infrared (IrDA, infrared Data Association) communication module, a WFD (Wi-Fi Direct) communication module, an UWB (ultrawideband) communication module, an Ant+ communication module, a microwave (uWave) communication module, etc.

[0072] The remote communication module may include a communication module that performs various types of remote communication and may include a mobile communication unit. The mobile communication unit transmits and receives wireless signals with at least one of a base station, an external terminal, and a server on a mobile communication network.

[0073] The indoor unit communication unit can communicate with external devices such as servers, mobile devices, and other home appliances through a nearby access point (AP). The access point (AP) can connect a local area network (LAN) to which the air conditioner or user device is connected to a wide area network (WAN) to which the server is connected. The air conditioner or user device can be connected to the server through the wide area network (WAN). The indoor unit of the air conditioner may include an indoor unit control unit that controls components of the indoor unit, including a blower, etc. The outdoor unit of the air conditioner may include an outdoor unit control unit that controls components of the outdoor unit, including a compressor, etc. The indoor unit control unit can communicate with the outdoor unit control unit through the indoor unit communication unit and the outdoor unit communication unit. The outdoor unit communication unit can transmit control signals generated by the outdoor unit control unit to the indoor unit communication unit, or transmit control signals transmitted from the indoor unit communication unit to the outdoor unit control unit. In other words, the outdoor unit and the indoor unit can communicate bidirectionally. The outdoor unit and the indoor unit can transmit and receive various signals generated during the operation of the air conditioner.

[0074] The outdoor unit control unit can be electrically connected to components of the outdoor unit and control the operation of each component. For example, the outdoor unit control unit can adjust the frequency of the compressor and control the flow switching valve to change the circulation direction of the refrigerant. The outdoor unit control unit can adjust the rotation speed of the outdoor fan. In addition, the outdoor unit control unit can generate a control signal to adjust the opening degree of the expansion valve. Under the control of the outdoor unit control unit, the refrigerant can circulate along a refrigerant circulation circuit including the compressor, the flow switching valve, the outdoor heat exchanger, the expansion valve, and the indoor heat exchanger.

[0075] The various temperature sensors included in the outdoor and indoor units can transmit electrical signals corresponding to the detected temperatures to the outdoor unit control unit and / or the indoor unit control unit. For example, the humidity sensors included in the outdoor and indoor units can transmit electrical signals corresponding to the detected humidity to the outdoor unit control unit and / or the indoor unit control unit.

[0076] The indoor unit control unit can obtain user input from a user device, including a mobile device, via the indoor unit communication unit, and can obtain user input directly through the input interface or via a remote controller. The indoor unit control unit can control components of the indoor unit, including a blower, in response to the received user input. The indoor unit control unit can transmit information regarding the received user input to the outdoor unit control unit of the outdoor unit.

[0077] The outdoor unit control unit can control the components of the outdoor unit, including the compressor, based on information regarding user input received from the indoor unit. For example, when a control signal corresponding to a user input for selecting an operation mode, such as cooling operation, heating operation, ventilation operation, defrosting operation, or dehumidification operation, is received from the indoor unit, the outdoor unit control unit can control the components of the outdoor unit so that the air conditioner performs an operation corresponding to the selected operation mode.

[0078] The outdoor unit control unit and the indoor unit control unit may each include a processor and a memory. The indoor unit control unit may include at least one first processor and at least one first memory, and the outdoor unit control unit may include at least one second processor and at least one second memory.

[0079] The memory can store / remember various information necessary for the operation of the air conditioner. The memory can store instructions, applications, data, and / or programs necessary for the operation of the air conditioner. For example, the memory can store various programs for the cooling, heating, dehumidifying, and / or defrosting operations of the air conditioner. The memory can include volatile memory such as Static Random Access Memory (S-RAM) and Dynamic Random Access Memory (DRAM) for temporarily storing data. In addition, the memory can include non-volatile memory such as Read Only Memory (ROM), Erasable Programmable Read Only Memory (EPROM), and Electrically Erasable Programmable Read Only Memory (EEPROM) for long-term storage of data.

[0080] The processor can generate control signals for controlling the operation of the air conditioner based on instructions, applications, data, and / or programs stored in memory. The processor, as hardware, may include logic circuits and arithmetic circuits. The processor can process data according to programs and / or instructions provided from the memory and generate control signals based on the processing results. The memory and the processor may be implemented as a single control circuit or as multiple circuits.

[0081] A processor may include various processing circuits and / or multiple processors. For example, the term “processor” as used herein, including in the claims, may include various processing circuits, including at least one processor. One or more processors in at least one processor may be configured to perform various functions described herein, individually and / or collectively, in a distributed fashion. As used herein, “processor,” “at least one processor,” and “one or more processors” may be configured to perform multiple functions. However, these terms encompass, without limitation, situations where one processor performs some of the functions and other processor(s) perform other parts of the functions, and situations where a single processor may perform all of the functions. Furthermore, at least one processor may include a combination of processors that perform various of the disclosed functions in a distributed manner. At least one processor may execute program instructions to achieve or perform various functions.

[0082] An indoor unit of an air conditioner may include an output interface. The output interface is electrically connected to the indoor unit control unit and can output information related to the operation of the air conditioner under the control of the indoor unit control unit. For example, information such as an operating mode selected by a user input, wind direction, wind volume, and temperature may be output. Additionally, the output interface may output sensing information obtained from an indoor unit sensor or an outdoor unit sensor, as well as warning / error messages.

[0083] The output interface may include a display and a speaker. The speaker, as an audio device, can output various sounds. The display may display information input by the user or information provided to the user using various graphic elements. For example, operation information of an air conditioner may be displayed as at least an image or text. The display may also include an indicator that provides specific information. The display may include a liquid crystal display panel (LCD), a light emitting diode panel (LED), an organic light emitting diode panel (OLED), a micro LED panel, and / or a plurality of LEDs.

[0084] Hereinafter, air conditioners according to various embodiments will be specifically described with reference to the drawings.

[0085] FIG. 1 is a drawing showing the structure and operation of an air conditioner according to one embodiment of the present disclosure.

[0086] According to one embodiment of the present disclosure, an air conditioner (100) performs an air conditioning operation for a target space (140a and 140b). The air conditioning operation may include, for example, cooling, heating, air purification, dehumidification, or ventilation. The air conditioner (100) may be implemented in the form of an air conditioner, a heater, an air conditioner, an air purifier, or a dehumidifier. In the present disclosure, the case where the air conditioner (100) corresponds to an air conditioner will be described mainly. However, this is for convenience of explanation, and the embodiments of the present disclosure are not limited thereto.

[0087] According to one embodiment of the present disclosure, an air conditioner (100) includes an outdoor unit (110) and a plurality of indoor units (120a and 120b). The number of the plurality of indoor units (120a and 120b) may be determined in various ways, such as two or more. In the present disclosure, the plurality of indoor units (120a and 120b) are collectively referred to as identification number 120. The plurality of indoor units (120) may include a combination of various types of indoor units, such as a stand-alone type, a wall-mounted type, or a system air conditioner.

[0088] A plurality of indoor units (120) may be placed in different target spaces (140a and 140b). For example, a first indoor unit (120a) may be placed in a first space (140a), and a second indoor unit (120b) may be placed in a second space (140b). The target spaces (140a and 140b) corresponding to each indoor unit (120) are spaces that are targets of the air conditioning operation of each indoor unit (120), and may correspond to spaces that are within a predetermined distance from the indoor unit (120) and are not blocked from the indoor unit (120) by a wall. The target spaces (140a and 140b) may correspond to various spaces, such as a living room, a bedroom, a study, and a kitchen, for example. The target space refers to an indoor space in which the indoor unit (120) can be installed.

[0089] The outdoor unit (110) may include a condenser and a compressor. Each of the plurality of indoor units (120) may include an expansion valve and an evaporator. The condenser may correspond to the outdoor heat exchanger, and the evaporator may correspond to the indoor heat exchanger. The heat pump device of the air conditioner (100) may include the condenser and compressor of the outdoor unit (110) and the expansion valve and evaporator of each of the plurality of indoor units (120). The heat pump device may perform a heat exchange operation by circulating a refrigerant through a refrigerant pipe connecting the condenser, the compressor, the evaporator, and the expansion valve. The air conditioner (100) may operate the heat pump device while performing a cooling or heating operation.

[0090] The condenser and compressor of the outdoor unit (110) may be connected to the expansion valve and evaporator of each of the plurality of indoor units (120). That is, the condenser and compressor of the outdoor unit (110) may be connected to the expansion valve and evaporator of the first indoor unit (120a). In addition, the condenser and compressor of the outdoor unit (110) may be connected to the expansion valve and evaporator of the second indoor unit (120b).

[0091] The air conditioner (100) uses oil for lubrication to protect the compressor from mechanical friction. The oil inside the compressor circulates through the refrigerant cycle inside the heat pump device together with the refrigerant discharged from the compressor. If the refrigerant circulates through the refrigerant pipe while mixed with oil, the oil may spread to the refrigerant pipe, condenser, expansion valve, or evaporator, thereby interfering with the circulation of the refrigerant. In addition, the oil discharged from the compressor may reduce the amount of oil inside the compressor, which may deteriorate the performance of the compressor. To prevent such adverse effects, the air conditioner (110) may perform an oil recovery operation to periodically return oil to the compressor.

[0092] The air conditioner (100) performs oil recovery operation by circulating a two-phase refrigerant through a heat pump device. The two-phase refrigerant is a refrigerant in which two phases coexist, and is a refrigerant in a mixed state of a liquid refrigerant and a gaseous refrigerant. The air conditioner (100) can generate the two-phase refrigerant by stopping the supercooling process of the refrigerant and increasing the temperature of the refrigerant. The two-phase refrigerant is a refrigerant in a state similar to boiling. The air conditioner (100) can separate the oil distributed in the refrigerant pipe, condenser, expansion valve, or evaporator by circulating the two-phase refrigerant through the heat pump device and recover it to the compressor through the refrigerant. However, since the two-phase refrigerant is a mixture of a gaseous refrigerant and a liquid refrigerant, noise is generated in the indoor unit (120) when the two-phase refrigerant is circulated through the heat pump device. This noise causes discomfort to the occupants (150a, 150b) around the indoor unit (120). If the power of the indoor unit (120) is turned off, the unexpected noise may cause discomfort to the occupants (150a, 150b).

[0093] According to one embodiment of the present disclosure, when the power of the indoor unit (120) is turned off, the air conditioner (100) can control the oil recovery operation in step 162 based on the result of detecting an occupant in the target space. For example, the air conditioner (100) may not perform the oil recovery operation in the indoor unit (120) that is turned off, or may reduce the amount of two-phase refrigerant circulated during the oil recovery operation. The air conditioner (100) can perform the oil recovery operation by circulating the two-phase refrigerant in the indoor unit (120b) that is in the operating state with the power turned on in step 160. In the present disclosure, the indoor unit (120) being in the off state means that the power of the corresponding indoor unit (120) among the plurality of indoor units (120) is turned off. In the present disclosure, the indoor unit (120) being in an operating state means that the power of the indoor unit (120) among the plurality of indoor units (120) is turned on.

[0094] According to one embodiment of the present disclosure, the air conditioner (100) has an effect of preventing noise from being generated in the indoor unit (120) in the off state due to oil recovery operation based on the result of occupant detection in the indoor unit (120) in the off state, thereby causing discomfort to the occupant.

[0095] FIG. 2 is a drawing showing the structure of an air conditioner according to one embodiment of the present disclosure.

[0096] An air conditioner according to one embodiment of the present disclosure may include an outdoor unit (110) and a plurality of indoor units (120a, 120b, and 120c).

[0097] The outdoor unit (110) and each indoor unit (120a, 120b, 120c) can transmit and receive control signals and data through a communication line. In addition, the outdoor unit (110) and each indoor unit (120a, 120b, and 120c) can circulate refrigerant through refrigerant pipes (130a, 130b, 130c).

[0098] The air conditioner (100) may include a heat pump device to perform a cooling function or a heating function. The heat pump device may include a refrigeration cycle in which a refrigerant is circulated along a compressor (222), an evaporator (218) (or a first heat exchanger), an expansion valve (216), and a condenser (220) (or a second heat exchanger). The air conditioner (100) may include refrigerant pipes (130a, 130b, and 130c) connecting the compressor (222), the condenser (220), the expansion valve (216), and the evaporator (218). The refrigerant may be circulated to the compressor (222), the condenser (220), the expansion valve (216), and the evaporator (218) through the refrigerant pipes (130a, 130b, and 130c).

[0099] An air conditioner (100) according to one embodiment of the present disclosure may correspond to a cooling device that performs a cooling operation. The outdoor unit (110) may include a condenser (220) and a compressor (222). In addition, the indoor unit (120) may include an expansion valve (216) and an evaporator (218).

[0100] The condenser (220) can perform heat exchange between the refrigerant and air by utilizing a phase change (e.g., condensation) of the refrigerant. For example, while the refrigerant is condensed in the condenser (220), the refrigerant can release heat to the air. As the heated air passes through the high-temperature condenser (220) and is blown outside the outdoor unit (110), the heat absorbed indoors can be released to the outside.

[0101] The compressor (222) compresses the refrigerant, thereby increasing its pressure and converting the refrigerant into a high-temperature, high-pressure state. The refrigerant in the heat pump device circulates due to the pressure of the compressor (222). The compressor (220) may include oil to protect the compressor (220) from mechanical friction.

[0102] The evaporator (218) can perform heat exchange between the refrigerant and air by utilizing a phase change (e.g., evaporation) of the refrigerant. For example, the refrigerant flowing in the evaporator (218) can absorb heat from the air while evaporating. The cooled air passing through the cooled evaporator (218) is then blown into the target space, thereby cooling the target space.

[0103] The expansion valve (216) lowers the pressure of the refrigerant, and as the pressure decreases, the temperature of the refrigerant decreases. The expansion valve (216) can lower the temperature and pressure of the refrigerant, for example, by utilizing a throttling effect. The expansion valve (216) may include an orifice that can reduce the cross-sectional area of ​​the flow path. The temperature and pressure of the refrigerant passing through the orifice may decrease.

[0104] According to one embodiment of the present disclosure, the expansion valve (216) may be implemented as an electronic expansion valve (EEV) capable of controlling the opening degree (i.e., the degree of opening of the valve). The amount of refrigerant passing through the expansion valve (216) may be controlled depending on the opening degree of the EEV. For example, 0% may mean that the valve is completely closed, and 100% may mean that the valve is completely open. As the opening degree increases, the flow rate of the refrigerant may increase. According to one embodiment of the present disclosure, the opening degree of the expansion valve (216) may correspond to a plurality of steps. For example, the expansion valve (216) may have 880 steps, and 0 step may correspond to a closed state, and 880 steps may correspond to a fully opened state. As the number of steps increases, the opening degree of the expansion valve (216) may increase.

[0105] Each of the indoor units (120a, 120b, and 120c) may include an expansion valve (216) and an evaporator (218). Each of the indoor units (120a, 120b, and 120c) may operate the expansion valve (216) and the evaporator (218) when in an operating state. Each of the indoor units (210a, 120b, and 120c) may stop the operation of the expansion valve (216) and the evaporator (218) when in an off state. The outdoor unit (110) may operate the condenser (220) and the compressor (222) when at least one of the indoor units (120a, 120b, and 120c) is in an operating state. The outdoor unit (110) can stop the operation of the condenser (220) and compressor (220) when all of the indoor units (120a, 120b, and 120c) are in the off state.

[0106] Each indoor unit (120a, 120b, and 120c) may include a processor (210), a detection sensor (212), a memory (214), an expansion valve (216), and an evaporator (218).

[0107] The processor (210) controls the overall operation of the air conditioner (100). The processor (210) may be implemented with one or more processors. One or more processors included in the processor (210) may be circuitry such as a System on Chip (SoC), an Integrated Circuit (IC), etc. The processor (210) may execute instructions or commands stored in the memory (214) to perform a predetermined operation. In addition, the processor (210) controls the operation of components provided in the air conditioner (100). One or more processors included in the processor (220) may be a general-purpose processor such as a CPU (Central Processing Unit), an MPU (Micro Processor Unit), an AP (Application Processor), a DSP (Digital Signal Processor), a graphics-only processor such as a GPU (Graphics Processing Unit), a VPU (Vision Processing Unit), an artificial intelligence-only processor such as an NPU (Neural Processing Unit), or a communication-only processor such as a CP (Communication Processor). When one or more processors included in the processor (210) are artificial intelligence-only processors, the artificial intelligence-only processor may be designed with a hardware structure specialized for processing a specific artificial intelligence model.

[0108] The processor (210) can write data to the memory (214) or read data stored in the memory (214), and in particular, process data according to predefined operation rules or artificial intelligence models by executing a program or at least one instruction stored in the memory (214). Accordingly, the processor (210) can perform operations described in the following embodiments, and operations described as being performed by the air conditioner (100) or detailed components included in the air conditioner (100) in the following embodiments can be regarded as being performed by the processor (210) unless otherwise specifically described.

[0109] The detection sensor (212) can detect an object in a target space. The detection sensor (212) may include, for example, a ToF (Time of Flight) sensor, an ultrasonic sensor, an infrared sensor, an optical sensor, a RADAR (radio detection and ranging) sensor, or a LiDAR (light detection and ranging) sensor. The detection sensor (212) is arranged to output a signal to the target space and detect a reflected signal. The detection sensor (212) may be arranged in front of the air conditioner (100) toward the target space. The detection sensor (212) generates a sensor detection value and transmits it to the processor (210).

[0110] The processor (210) determines whether there is a moving object using the sensor detection value of the detection sensor (212), and if there is a moving object, determines that there is a person in the target space. According to one embodiment of the present disclosure, the processor (210) determines whether the detected object is a person using the sensor detection value. For example, if the detection sensor (212) corresponds to an infrared sensor, the processor (210) determines that there is a person in the target space if an infrared value corresponding to a person is detected. According to one embodiment of the present disclosure, the processor (210) determines whether the detected object has a human shape based on the sensor detection value, and if the detected object corresponds to a human shape, determines that there is a human, i.e., an occupant, in the target space.

[0111] In this disclosure, people within the target space may be referred to as users, occupants, etc.

[0112] According to one embodiment of the present disclosure, the detection sensor (212) corresponds to a radar sensor, and the processor (210) can determine whether a detected object is a human figure using a sensor detection value of the radar sensor. The radar sensor outputs a radar signal to a target space, and detects a signal reflected from an object in the target space as a sensor detection value. The processor (210) detects an object in the target space using the sensor detection value of the radar sensor. The processor (210) detects an object in the target space at a predetermined frame rate, and detects movement of the object. The processor (210) determines that an occupant exists in the target space if the movement value of the object in the target space is greater than or equal to a reference value. For example, the processor (210) detects an object in the target space at a cycle of 30 frames / sec, and determines that an occupant exists in the target space if the movement value per second of the object is greater than or equal to a reference value.

[0113] In addition, according to one embodiment of the present disclosure, the processor (210) determines whether the recognized object is a person based on the result of object recognition based on the sensor detection value of the radar sensor. For example, the processor (210) can determine whether the recognized object is a person based on the shape of the recognized object. If the recognized object corresponds to a person and the movement value is greater than or equal to a reference value, the processor (210) determines that an occupant exists in the target space. If the processor (210) determines that the recognized object does not correspond to a person, the processor (210) determines that an occupant does not exist in the target space. In addition, according to one embodiment of the present disclosure, the processor (210) can determine that an occupant exists in the target space even when the recognized object corresponds to a pet. Therefore, the processor (210) can determine that an occupant exists in the target space if the detected object corresponds to a person or a pet and the movement value is greater than or equal to a reference value.

[0114] According to one embodiment of the present disclosure, the processor (210) can calculate the distance from the indoor unit (120) to the occupant using the sensor detection value of the detection sensor (212). According to one embodiment of the present disclosure, the detection sensor (212) corresponds to a ToF sensor, and can calculate the distance to the occupant using the detection value of the ToF sensor.

[0115] In addition, according to one embodiment of the present disclosure, the processor (210) may obtain location information of an occupant using a sensor detection value of the detection sensor (212), and calculate a distance from the indoor unit (120) to the occupant based on the location information. The location information of the occupant may be defined as coordinate information within a target space. In addition, according to one embodiment of the present disclosure, the location information of the occupant may be defined as an area or range in which the occupant exists within the target space. The accuracy of the location information of the occupant may vary depending on the type of the detection sensor (212). For example, when the detection sensor (212) corresponds to an infrared sensor, the location information of the occupant may be defined as an area or range. In addition, for example, when the detection sensor (212) corresponds to a radar sensor, the location information of the person may be defined as coordinate information. The processor (210) may measure the distance from the indoor unit (120) to the occupant based on the location information of the indoor unit (120) and the location information of the occupant. The distance from the indoor unit (120) to the occupant can be measured as a straight line distance or as a distance projected onto the floor.

[0116] According to one embodiment of the present disclosure, the air conditioner (100) can perform an oil recovery operation to recover oil using the compressor (222), as described above. According to one embodiment of the present disclosure, the air conditioner (100) can perform the oil recovery operation whenever the accumulated operation time of the outdoor unit (110) reaches the oil recovery cycle. In addition, according to one embodiment of the present disclosure, the air conditioner (100) can perform the oil recovery operation when the state of the air conditioner (100) satisfies a predetermined condition. According to one embodiment of the present disclosure, the oil recovery operation can be controlled by a processor (not shown) provided in the outdoor unit (110). In addition, according to one embodiment of the present disclosure, the oil recovery operation can be performed by one processor (210) of a plurality of indoor units (120). A processor (at least one processor of the outdoor unit (110) or the indoor unit (120)) that controls the oil recovery operation in the air conditioner (100) can control the oil recovery operation while communicating with the outdoor unit (110) and a plurality of indoor units (120). Although the present disclosure focuses on an embodiment in which one processor (210) of the indoor units (120) controls the oil recovery operation, the present disclosure is not limited thereto. In addition, it is also possible for a plurality of processors within the air conditioner (100) (for example, a processor of the outdoor unit (110) and a processor (210) of the first indoor unit (120a)) to jointly control the oil recovery operation.

[0117] The processor (210) starts the oil recovery operation when the conditions for performing the oil recovery operation are satisfied. When starting the oil recovery operation, if there is an indoor unit (120) in an off state, the processor (210) determines whether to perform the oil recovery operation in the indoor unit (120) in the off state. The processor (210) determines whether an occupant is present in the target space of the indoor unit (120) in the off state using the detection sensor (212) of the indoor unit (120) in the off state. The processor (210) can control the oil recovery operation of the indoor unit (120) in the off state based on the occupant detection result. According to one embodiment of the present disclosure, the processor (210) can control the oil recovery operation by controlling the open state of the expansion valve (216) of the indoor unit (120) in the off state based on the occupant detection result.

[0118] According to one embodiment of the present disclosure, when there is no occupant in the target space of the indoor unit (120) in the off state, the processor (210) can control the indoor unit (120) in the off state to perform an oil recovery operation. For example, when there is no occupant, the processor (210) can open the expansion valve (216) of the indoor unit (120) in the off state to the maximum to perform the oil recovery operation.

[0119] According to one embodiment of the present disclosure, when an occupant exists in a target space of an indoor unit (120) that is in an off state, the processor (210) can control the degree of opening of the expansion valve (216) based on the distance from the indoor unit (120) that is in an off state to the occupant. For example, when an occupant exists within a first distance from the indoor unit (120) that is in an off state, the processor (210) can control the expansion valve (216) to be closed, thereby preventing oil recovery operation from being performed in the indoor unit (120) that is in an off state. In addition, for example, when an occupant exists beyond the first distance from the indoor unit (120) that is in an off state, the processor (210) can control the opening step of the expansion valve (216) according to the distance to the occupant. For example, when an occupant exists beyond the first distance, the processor (210) can increase the opening step of the expansion valve (216) as the distance from the indoor unit (120) to the occupant increases.

[0120] When there are two or more indoor units (120) in the off state, the processor (210) can individually control the oil recovery operation according to the occupant detection result of each indoor unit (120) in the off state. For example, assume that the first indoor unit (120a) and the second indoor unit (120b) are in the off state, and the third indoor unit (120c) is in the operating state. There is no occupant in the first space where the first indoor unit (120a) is installed, and there is an occupant within the first distance in the second space where the second indoor unit (120b) is installed. In this case, the processor (210) can open the expansion valve (216) in the first indoor unit (120a) to perform the oil recovery operation, and close the expansion valve (216) in the second indoor unit (120b) to not perform the oil recovery operation.

[0121] The processor (210) performs oil recovery operation in the indoor unit (120) in operation state.

[0122] According to one embodiment of the present disclosure, the processor (210) can detect an occupant in real time using the detection sensor (212) of each indoor unit (120) while performing an oil recovery operation, and control the oil recovery operation based on the real-time occupant detection result. For example, when starting the oil recovery operation, if the first indoor unit (120a) is in the off state and there is no occupant in the first space, the first indoor unit (120a) performs the oil recovery operation. Thereafter, if an occupant is detected in the first space during the oil recovery operation, the processor (210) can stop the oil recovery operation or reduce the opening step of the expansion valve (216) depending on the distance from the occupant.

[0123] The memory (214) stores various information, data, commands, programs, etc. required for the operation of the air conditioner (100). The memory (214) may include at least one of volatile memory and non-volatile memory, or a combination thereof. The memory (214) may include at least one type of storage medium among a flash memory type, a hard disk type, a multimedia card micro type, a card type memory (e.g., SD or XD memory, etc.), a RAM (Random Access Memory), a SRAM (Static Random Access Memory), a ROM (Read-Only Memory), an EEPROM (Electrically Erasable Programmable Read-Only Memory), a PROM (Programmable Read-Only Memory), a magnetic memory, a magnetic disk, and an optical disk. In addition, the memory (214) may correspond to a web storage or cloud server that performs a storage function on the Internet.

[0124] FIG. 3 is a flowchart illustrating an air conditioner control method according to one embodiment of the present disclosure.

[0125] An air conditioner control method according to one embodiment of the present disclosure may be performed by an air conditioner (100) according to one embodiment of the present disclosure. However, the embodiment of the present disclosure is not limited to performing the air conditioner control method by the air conditioner (100) of the present disclosure, and the air conditioner control method may be performed by various types of air conditioners.

[0126] Referring to FIG. 3, the air conditioner (100) performs an oil recovery operation in step S302. The air conditioner (100) may perform the oil recovery operation whenever the accumulated operation time of the outdoor unit (110) reaches the oil recovery cycle. In addition, according to one embodiment of the present disclosure, the air conditioner (100) may perform the oil recovery operation when the state of the air conditioner (100) satisfies a predetermined condition. In step S302, the air conditioner (100) may perform preparations for the oil recovery operation before starting the circulation of the two-phase refrigerant for the oil recovery operation. The preparations for the oil recovery operation may include an operation of monitoring the power on / off status of a plurality of indoor units (120).

[0127] Next, the air conditioner (100) determines whether the power is turned off for each of the plurality of indoor units (120) in step S304.

[0128] In the case where there is an indoor unit (120) that is in an off state among a plurality of indoor units (120), the air conditioner (100) detects an occupant in the target space using the detection sensor (212) of the indoor unit (120) that is in an off state in step S306. The air conditioner (100) can detect whether an occupant exists in the target space of the indoor unit (120) that is in an off state, and if an occupant exists, the distance to the occupant.

[0129] The air conditioner (100) can then control the oil recovery operation by controlling the open state of the expansion valve (216) of the indoor unit (120) in the off state based on the result of the occupant detection in step S308.

[0130] According to one embodiment of the present disclosure, when there is no occupant in the target space of the indoor unit (120) in the off state, the air conditioner (100) can be controlled to perform an oil recovery operation in the indoor unit (120) in the off state. For example, when there is no occupant, the air conditioner (100) can perform an oil recovery operation by opening the expansion valve (216) of the indoor unit (120) in the off state to the maximum.

[0131] According to one embodiment of the present disclosure, when an occupant exists in a target space of an indoor unit (120) in an off state, the air conditioner (100) can control the degree of opening of the expansion valve (216) based on the distance from the indoor unit (120) in an off state to the occupant. For example, when an occupant exists within a first distance from the indoor unit (120) in an off state, the air conditioner (100) can control the expansion valve (216) to a closed state so as not to perform an oil recovery operation in the indoor unit (120) in an off state. In addition, for example, when an occupant exists beyond the first distance from the indoor unit (120) in an off state, the air conditioner (100) can control the opening step of the expansion valve (216) based on the distance to the occupant. For example, when there is an occupant at a distance exceeding the first distance, the air conditioner (100) can increase the opening step of the expansion valve (216) as the distance from the indoor unit (120) to the occupant increases.

[0132] If the air conditioner (100) determines that the indoor unit (120) is in an operating state with the power turned on in step S304, the air conditioner (100) can perform an oil recovery operation in the indoor unit (120) in the operating state. The air conditioner (100) can perform an oil recovery operation by opening the expansion valve (216) to the maximum step in the indoor unit (120) in the operating state.

[0133] The air conditioner (100) determines whether the power is off for each indoor unit (120) in step S304, and may perform steps S306 and S308 or perform oil recovery operation based on the determination result.

[0134] FIG. 4 is a drawing for explaining the operation of oil recovery operation of an air conditioner according to one embodiment of the present disclosure.

[0135] Referring to FIG. 4, an operation of controlling an oil recovery operation of an air conditioner (100) according to the status of a plurality of indoor units (120a, 120b, and 120c) will be described. According to one embodiment of the present disclosure, when a condition for performing an oil recovery operation is met, the air conditioner (100) starts the oil recovery operation. The air conditioner (100) first detects whether each of the plurality of indoor units (120a, 120b, and 120c) is in operation. FIG. 4 illustrates a case where a first indoor unit (120a) is in an operation state and a second indoor unit (120b) and a third indoor unit (120c) are in an off state.

[0136] When the air conditioner (100) detects that the second indoor unit (120b) and the third indoor unit (120c) are in the off state, it obtains the occupant detection result from the second indoor unit (120b) and the third indoor unit (120c).

[0137] If an occupant is detected in the target space of the second indoor unit (120b), the air conditioner (100) may not perform an oil recovery operation in the second indoor unit (120b). The air conditioner (100) may control the expansion valve (216) of the second indoor unit (120b) to be closed, so as not to perform the oil recovery operation. In addition, according to one embodiment of the present disclosure, if an occupant is present further away than the first distance from the second indoor unit (120b), the air conditioner (100) may control the open step of the expansion valve (216) of the second indoor unit (120b), so as to perform the oil recovery operation. The second indoor unit (120b) may open the expansion valve (216) at a predetermined open step.

[0138] If no occupants are detected in the target space of the third indoor unit (120c), the air conditioner (100) can perform oil recovery operation in the third indoor unit (120c). The air conditioner (100) can perform oil recovery operation by controlling the expansion valve (216) of the second indoor unit (120b) to an open state.

[0139] The air conditioner (100) can control the expansion valve (216) of the first indoor unit (120a) in the operating state to be open. The expansion valve (216) of the first indoor unit (120a) can be controlled to be in the maximum open state.

[0140] When the air conditioner (100) completes the control of the open state of the expansion valve (216) of the first indoor unit (120a), the second indoor unit (120b), and the third indoor unit (120c), it circulates the two-phase refrigerant through the outdoor unit (110) and the plurality of indoor units (120). At this time, the two-phase refrigerant is not circulated to the indoor unit (120) whose expansion valve (216) is in the closed state, and the oil recovery operation is skipped.

[0141] According to one embodiment of the present disclosure, the air conditioner (100) can monitor the on / off status of the power of a plurality of indoor units (120) and the result of occupancy detection while performing oil recovery operation.

[0142] If there is an indoor unit (120) among a plurality of indoor units (120) whose power on / off state is changed during the oil recovery operation, the air conditioner (100) can change the open state of the expansion valve (216) of the indoor unit (120) whose power on / off state is changed. According to one embodiment of the present disclosure, if the power of the indoor unit (120) is changed from the operating state to the off state during the oil recovery operation, the air conditioner (100) can maintain the expansion valve (216) in the open state and perform the oil recovery operation as is. If the power of the air conditioner (100) is changed from the off state to the operating state during the oil recovery operation, the air conditioner (100) can open the expansion valve (216) to the maximum to perform the oil recovery operation.

[0143] If there is an indoor unit (120) in which the result of occupancy detection has changed during the oil recovery operation among the indoor units (120) in the off state, the air conditioner (100) can change the open state of the expansion valve (216) of the indoor unit (120) in which the result of occupancy detection has changed. According to one embodiment of the present disclosure, if the state in which occupancy is not detected during the oil recovery operation has changed to the state in which occupancy is detected, the air conditioner (100) can maintain the expansion valve (216) in the open state and continue to perform the oil recovery operation. If the state in which occupancy is detected has changed to the state in which occupancy is not detected, the air conditioner (100) can open the expansion valve (216) to the maximum to perform the oil recovery operation.

[0144] FIG. 5 is a flowchart illustrating a process of performing oil recovery operation according to one embodiment of the present disclosure.

[0145] According to one embodiment of the present disclosure, if the oil recovery operation conditions are satisfied, the air conditioner (100) can prepare for oil recovery operation in step S502. Step S502 of preparing for oil recovery operation may be an operation included in step S302 described above in FIG. 3.

[0146] Next, in step S304, the air conditioner (100) monitors the on / off status of the power of multiple indoor units (120) and determines whether there is an indoor unit (120) in an off state.

[0147] The indoor unit (120) in the operating state can perform oil recovery operation by automatically controlling the expansion valve (216) in step S508. According to one embodiment of the present disclosure, the air conditioner (100) can open the expansion valve (216) of the indoor unit (120) in the operating state to the maximum.

[0148] The indoor unit (120) in the off state initiates the operation of the detection sensor (212) in step S504. The indoor unit (120) can detect an occupant in the target space using the detection sensor (212) in step S506.

[0149] The indoor unit (120) in the off state can open the expansion valve (216) of the indoor unit (120) to the maximum in step S510 when there is no occupant in the target space.

[0150] Steps S504 and S506 may correspond to step S306 of FIG. 3. Steps S508 and S510 may correspond to step S308 of FIG. 3.

[0151] When the control of the expansion valves (216) of the plurality of indoor units (120) is completed, the air conditioner (100) performs an oil recovery operation in step S512. The air conditioner (100) initiates the circulation of the two-phase refrigerant and performs the oil recovery operation.

[0152] Next, the air conditioner (100) determines whether the oil recovery operation has been completed at step S514. For example, the air conditioner (100) may terminate the oil recovery operation after performing the oil recovery operation for a predetermined period of time. Additionally, for example, the air conditioner (100) may terminate the oil recovery operation if a predetermined condition is satisfied.

[0153] If the oil recovery operation is not completed, the air conditioner (100) returns to step S304 and performs the following operations. If the oil recovery operation is completed, the air conditioner (100) automatically controls the expansion valve (216) of the indoor unit (120) in step S516. For example, the air conditioner (100) may close all expansion valves (216) of the indoor units (120) in step S516 and then open the expansion valves (216) again to perform the air conditioning operation being performed. For example, the air conditioner (100) may close all expansion valves (216) of a plurality of indoor units (120) after completing the circulation of the two-phase refrigerant, and open the expansion valves (216) of the indoor units (120) in the operating state while starting the circulation of the refrigerant in the supercooled state. The air conditioner (100) can keep the expansion valve (216) of the indoor unit (120) in the off state in a closed state.

[0154] Next, the operation when a person in the room is detected in step S506 is described with reference to FIG. 6.

[0155] FIG. 6 is a flowchart illustrating an oil recovery operation when an occupant is detected in a target space of an indoor unit in an off state according to one embodiment of the present disclosure.

[0156] According to one embodiment of the present disclosure, if an occupant is detected in the target space of the indoor unit (120) in step S506 of FIG. 5, the air conditioner (100) can determine whether the occupant exists within a first distance from the indoor unit (120) in step S602 of FIG. 6. The first distance may be defined as a distance between 1.5 m and 2.5 m, for example. If the occupant exists within the first distance from the indoor unit (120), the air conditioner (100) controls the expansion valve (216) to be closed in step S604.

[0157] If it is determined in step S602 of FIG. 6 that the occupant is not within the first distance, the air conditioner (100) can determine in step S606 whether the occupant is within a second distance from the indoor unit (120). The second distance corresponds to a distance longer than the first distance, and can be defined as a distance between 2.5 m and 3.5 m, for example. If the occupant is within the second distance from the indoor unit (120), the air conditioner (100) can open the expansion valve (216) in a first step in step S608. The first step may correspond to the minimum opening step of the expansion valve (216). For example, if the opening steps of the expansion valve (216) range from 0 to 880 steps, the first step may correspond to step 80.

[0158] In step S606 of FIG. 6, the air conditioner (100) can determine whether the occupant is within a third distance if the occupant is not within a second distance. The third distance corresponds to a distance longer than the second distance and can be defined as, for example, a distance between 3.5 and 5 m. If the occupant is within the third distance from the indoor unit (120), the air conditioner (100) can open the expansion valve (216) at a higher step than the first step. In this way, the air conditioner (100) can increase the opening step of the expansion valve (216) as the distance from the indoor unit (120) in the off state to the occupant increases.

[0159] The air conditioner (100) can determine whether an occupant is located beyond a predetermined reference distance in step S610. The reference distance may be defined as a sufficiently long distance from the indoor unit (120), for example, 10 to 15 m. If the occupant is located beyond the reference distance, the air conditioner (100) opens the expansion valve (216) to the Nth step in step S612. The Nth step may correspond to, for example, a maximum opening state.

[0160] Steps S602, S606, and S610 of FIG. 6 may be included in step S306 of FIG. 3. Steps S604, S608, and S612 of FIG. 6 may be included in step S308 of FIG. 3.

[0161] When the control of the expansion valve (216) is completed in steps S604, S608, and S612, the air conditioner (100) performs an oil recovery operation in step S512. The air conditioner (100) initiates the circulation of the two-phase refrigerant and performs the oil recovery operation.

[0162] Next, the air conditioner (100) determines whether the oil recovery operation has been completed at step S514. For example, the air conditioner (100) may terminate the oil recovery operation after performing the oil recovery operation for a predetermined period of time. Additionally, for example, the air conditioner (100) may terminate the oil recovery operation if a predetermined condition is satisfied.

[0163] If the oil recovery operation is not completed, the air conditioner (100) returns to step S304 and performs the following operations. If the oil recovery operation is completed, the air conditioner (100) automatically controls the expansion valve (216) of the indoor unit (120) in step S516.

[0164] FIG. 7 is a flowchart illustrating a process for determining performance conditions of an oil recovery operation according to one embodiment of the present disclosure.

[0165] According to one embodiment of the present disclosure, the air conditioner (100) can calculate the cumulative operation time of the outdoor unit (110) and perform oil recovery operation whenever the cumulative operation time reaches the oil recovery cycle.

[0166] The air conditioner (100) starts operation of the outdoor unit (110) when at least one indoor unit (120) is turned on in step S702. When operation of the outdoor unit (110) starts, the condenser (220) and compressor (222) operate, and the heat pump device circulates the refrigerant.

[0167] When the outdoor unit operation of the air conditioner (100) starts, the air conditioner (100) can calculate the cumulative operation time of the outdoor unit (110) in step S704. The air conditioner (100) can store the cumulative operation time of the outdoor unit (110) in the memory (not shown) of the outdoor unit (110) or in at least one memory (214) of the indoor unit (120). As the power of the indoor unit (120) is turned on / off, the power of the outdoor unit (110) is also turned on / off. The air conditioner (100) can calculate the cumulative operation time by accumulating the time that the outdoor unit (110) is operated in the turned-on state, excluding the time that it is turned off.

[0168] The air conditioner (100) can determine whether the accumulated operating time has reached the oil recovery cycle in step S706. The oil recovery cycle can be defined as a value between 1 and 4 hours, for example.

[0169] When the accumulated operation time of the air conditioner (100) reaches the oil recovery cycle, the air conditioner (100) performs oil recovery operation in step S708. The air conditioner (100) can perform oil recovery operation according to various embodiments disclosed in the present disclosure.

[0170] The air conditioner (100) determines whether the oil recovery operation is completed in step S710.

[0171] When the oil recovery operation is completed, the air conditioner (100) can reset the accumulated operation time in step S712. The accumulated operation time can be reset to 0. After the accumulated operation time is reset, the air conditioner (100) can calculate the accumulated outdoor unit operation time again in step S704 and repeat the following operations.

[0172] FIG. 8 is a block diagram showing the structure of an air conditioner according to one embodiment of the present disclosure.

[0173] In Fig. 8, parts overlapping with the description of Fig. 2 are omitted, and the differences from the air conditioner (100) of Fig. 2 are mainly explained.

[0174] Each indoor unit (120a, 120b, and 120c) according to one embodiment of the present disclosure may include a processor (210), a detection sensor (212), a memory (214), an expansion valve (216), an evaporator (218), a communication module (810), and an output interface (820).

[0175] The communication module (810) transmits signals or data to a server or an external device, and receives signals or data from the server or an external device. According to one embodiment of the present disclosure, the communication module (810) may transmit a message indicating that an oil recovery operation is being performed to an external device via the server. Additionally, the communication module (810) may communicate control signals and messages with the external device via the server.

[0176] Additionally, according to one embodiment of the present disclosure, the communication module (810) can communicate with a server via a network. The communication module (810) can connect to the network via an Access Point (AP) device and communicate with the server. The communication module (810) can transmit status information of the air conditioner (100) to the server to synchronize the status information of the server and the air conditioner (100). In addition, the communication module (810) can receive operation mode or setting information of the air conditioner (100) set using a user terminal or the like from the server.

[0177] The communication module (810) may include a wireless communication module (e.g., a cellular communication module, a short-range wireless communication module, or a GNSS (global navigation satellite system) communication module) or a wired communication module (e.g., a LAN (local area network) communication module, or a power line communication module). In addition, the communication module (810) may perform short-range communication, and may use, for example, Bluetooth, BLE (Bluetooth Low Energy), near field communication, WLAN (Wi-Fi), Zigbee, infrared (IrDA, infrared Data Association) communication, WFD (Wi-Fi Direct), UWB (ultrawideband), Ant+ communication, etc. In addition, for example, the communication module (810) may perform long-range communication, and may communicate with an external device through, for example, a legacy cellular network, a 5G network, a next-generation communication network, the Internet, or a computer network (e.g., a LAN or WAN).

[0178] Additionally, for example, the communication module (810) can utilize mobile communication and transmit and receive wireless signals with at least one of a base station, an external terminal, and a server on a mobile communication network.

[0179] According to one embodiment of the present disclosure, the communication module (810) is connected to an access point (AP) in the home via Wi-Fi communication. The communication module (810) can communicate with an external device via the access point.

[0180] The output interface (820) outputs signals or data related to the air conditioner (100). The output interface (820) may include, for example, a display, a speaker, an LED lamp, a touch screen, or a speaker.

[0181] According to one embodiment of the present disclosure, the communication module (810) and the output interface (820) may be provided in each of the plurality of indoor units (120a, 120b, and 120c). Furthermore, according to one embodiment of the present disclosure, the communication module (810) and the output interface (820) may be provided in only some of the plurality of indoor units (120a, 120b, and 120c). Furthermore, according to one embodiment of the present disclosure, the communication module (810) and the output interface (820) may be provided in the plurality of indoor units (120a, 120b, and 120c) with different specifications. For example, if among a plurality of indoor units (120a, 120b, and 120c), the first indoor unit (120a) is set as the main indoor unit, and the second indoor unit (120b) and the third indoor unit (120c) are set as sub indoor units, the first indoor unit (120a) may include a high-spec communication module (810), and the second indoor unit (120b) and the third indoor unit (120c) may include low-spec communication modules (810). For example, the first indoor unit (120a) may be configured to enable Wi-Fi communication, Bluetooth communication, and RS-485 serial communication, and the second indoor unit (120b) and the third indoor unit (120c) may be configured to enable Wi-Fi communication and RS-485 serial communication. Additionally, for example, the first indoor unit (120a) may include a display, a touch button, a speaker, and an LED lamp in the output interface (820), and the second indoor unit (120b) and the third indoor unit (120c) may include a speaker and an LED lamp.

[0182] FIG. 9 is a diagram illustrating an air conditioner, an external device, and a server according to one embodiment of the present disclosure.

[0183] According to one embodiment of the present disclosure, the air conditioner (100) communicates with an external device (910) and a server (920) through a communication module (not shown). The air conditioner (100) can be connected to other home appliances, an external device (910), or a server (920) through a network (NET).

[0184] The server (920) can manage user account information and information about the air conditioner (100) connected to the user account. For example, a user can access the server (920) via an external device (910) and create a user account. The user account can be identified by an ID and password set by the user. The server (920) can register the air conditioner (100) to the user account according to a set procedure. For example, the server (920) can register the air conditioner (100) by connecting identification information (e.g., serial number or MAC address) of the air conditioner (100) to the user account.

[0185] The external device (910) may include a communication module capable of communicating with the air conditioner (100) and the server (920), a user interface for receiving user input or outputting information to the user, at least one processor for controlling the operation of the external device (910), and at least one memory storing a program for controlling the operation of the external device (910).

[0186] The external device (910) may be carried by the user or placed in the user's home or office, etc. The external device (910) may include, but is not limited to, a personal computer, a terminal, a portable telephone, a smart phone, a handheld device, a wearable device, etc., for example.

[0187] The memory of the external device (910) may store a program (e.g., an application) for controlling the air conditioner (100). The external device (910) may be sold with the application for controlling the air conditioner (100) installed, or may be sold without the application installed. If the external device (910) is sold without the application for controlling the air conditioner (100) installed, the user may download the application from an external server providing the application and install it on the external device (910).

[0188] A user can control an air conditioner (100) using an application installed in an external device (910). For example, when a user executes an application installed in an external device (910), identification information of an air conditioner (100) connected to the same user account as the external device (910) may appear in an application execution window. The user can perform desired control of the air conditioner (100) through the application execution window. When a user inputs a control command for the air conditioner (100) through the application execution window, the external device (910) may transmit the control command directly to the air conditioner (100) through a short-range network, or may transmit the control command to the air conditioner (100) via a server (920).

[0189] The application of the external device (910) can receive various user inputs for controlling the air conditioner (100). The application provides a GUI (Graphical User Interface) for receiving various user inputs and receives user inputs through the GUI. The external device (910) communicates with the server (920) and updates status information of the air conditioner (100) and provides it to the application. In addition, the external device (910) communicates with the server (920) and transmits user inputs received through the application to the air conditioner (100).

[0190] The application can receive a power-off signal or a shutdown reservation signal from the air conditioner (100). Furthermore, the application can receive a reservation setting signal and user input for setting a reservation end time. Furthermore, the application can receive a sleep mode setting signal and user input for setting a reservation end time. Furthermore, the application can receive user input for setting a noise reduction mode. Furthermore, the application can receive user input for setting an automatic drying function. Furthermore, the application can receive user input for setting a wind-free mode.

[0191] A network (NET) can include both wired and wireless networks. Wired networks include cable networks or telephone networks, while wireless networks can include any network that transmits and receives signals via radio waves. Wired and wireless networks can be interconnected.

[0192] A network (NET) may include a wide area network (WAN) such as the Internet, a local area network (LAN) formed around an access point (AP), and a wireless personal area network (WPAN) that does not use an access point. Short-range wireless networks may include, but are not limited to, Bluetooth™ (IEEE 802.15.1), Zigbee (IEEE 802.15.4), Wi-Fi Direct, Near Field Communication (NFC), and Z-Wave.

[0193] An access point (AP) can connect a local area network (LAN) to which an air conditioner (100) and an external device (910) are connected to a wide area network (WAN) to which a server (920) is connected. The air conditioner (100) or an external device (910) can be connected to the server (920) via the wide area network (WAN).

[0194] An AP may include a device that enables devices to connect using Wi-Fi-related standards in a computer network.

[0195] According to embodiments of the present disclosure, the AP may include a hardware-implemented AP and a software-implemented AP.

[0196] For example, an AP can relay data between wireless devices and wired devices on a network. However, this is not limited to this; an AP can also relay data between wired devices or between wireless devices. Meanwhile, an AP can also be referred to as a relay device.

[0197] The access point (AP) can communicate with the air conditioner (100) and external devices (910) using wireless communication such as Wi-Fi (Wi-Fi™, IEEE 802.11), and can connect to a wide area network (WAN) using wired communication.

[0198] The air conditioner (100) can transmit information about its operation or status to the server (920) via a network (NET). For example, the air conditioner (100) can transmit information about its operation or status to the server (920) via Wi-Fi™ (IEEE 802.11) communication.

[0199] If the air conditioner (100) is not equipped with a Wi-Fi communication module, the air conditioner (100) can transmit information about its operation or status to the server (920) through another home appliance having a Wi-Fi communication module. For example, if the air conditioner (100) transmits information about its operation or status to another home appliance through a short-range wireless network (e.g., BLE (Bluetooth Low Energy) communication), the other home appliance can transmit information about the operation or status of the air conditioner (100) to the server (920). In addition, for example, if the air conditioner (100) is not equipped with a Wi-Fi communication module, the air conditioner (100) can be connected to a communication relay device by a wire and perform Wi-Fi communication and 485 communication through the communication relay device.

[0200] The air conditioner (100) may provide information regarding the operation or status of the air conditioner (100) to the server (920) with prior approval from the user. Information transmission to the server (920) may be performed when a request is received from the server (920), when a specific event occurs in the air conditioner (100), or periodically or in real time.

[0201] When information on the operation or status is received from the air conditioner (100), the server (920) can update information previously stored in relation to the air conditioner (100). The server (920) can transmit information on the operation or status of the air conditioner (100) to an external device (910) via a network (NET).

[0202] The server (920) can transmit information regarding the operation or status of the air conditioner (100) to the external device (910) when a request is received from the external device (910). For example, when a user runs an application connected to the server (920) on the external device (910), the external device (910) can request and receive information regarding the operation or status of the air conditioner (100) from the server (920) through the application. When information regarding the operation or status is received from the air conditioner (100), the server (920) can transmit information regarding the operation or status of the air conditioner (100) to the external device (910) in real time. The server (920) can also periodically transmit information regarding the operation or status of the air conditioner (100) to the external device (910). The external device (910) can transmit information about the operation or status of the air conditioner (100) to the user by displaying information about the operation or status of the air conditioner (100) in the application execution window.

[0203] The air conditioner (100) can obtain various information from the server (920) and provide the obtained information to the user. In addition, the air conditioner (100) can receive a file for updating pre-installed software or data related to pre-installed software from the server (920), and update the pre-installed software or data related to pre-installed software based on the received file.

[0204] The air conditioner (100) can operate according to a control command received from the server (920). For example, if the air conditioner (100) has obtained prior approval from a user to operate according to the control command of the server (920) even without user input, the air conditioner (100) can operate according to the control command received from the server (920). The control command received from the server (920) may include, but is not limited to, a control command input by the user through an external device (910) or a control command generated by the server (920) based on preset conditions.

[0205] FIG. 10 is a diagram illustrating an operation of an air conditioner outputting a notification during oil recovery operation according to one embodiment of the present disclosure.

[0206] According to one embodiment of the present disclosure, the air conditioner (100) can output a message indicating that oil recovery operation is in progress during oil recovery operation.

[0207] While the air conditioner (100) is performing an oil recovery operation, each of the plurality of indoor units (120a, 120b, and 120c) can output a message (1010) indicating that the oil recovery operation is in progress through an output interface (820). According to one embodiment of the present disclosure, the plurality of indoor units (120a, 120b, and 120c) can output a voice message through a speaker. In addition, according to one embodiment of the present disclosure, the plurality of indoor units (120a, 120b, and 120c) can display a message (1010) indicating that the oil recovery operation is in progress through a display.

[0208] According to one embodiment of the present disclosure, multiple indoor units (120a, 120b, and 120c) can output the message (1010) in different ways. For example, the first indoor unit (120a) and the second indoor unit (120b) can output the message (1010) as a voice message, and the third indoor unit (120c) can output the message (1010) as a voice message while displaying the message (1010) on the display of the output interface (820).

[0209] According to one embodiment of the present disclosure, the air conditioner (100) can output a message notifying that an oil recovery operation is in progress through an external device (910). When the air conditioner (100) starts the oil recovery operation, it can transmit information that the oil recovery operation is in progress to the external device (910) through a server (920). When the external device (910) receives information from the air conditioner (100) that the oil recovery operation is in progress, it can display a message (1010) indicating that the oil recovery operation is in progress through an application.

[0210] FIG. 11 is a flowchart illustrating a process of performing oil recovery operation according to one embodiment of the present disclosure.

[0211] According to one embodiment of the present disclosure, when performing an oil recovery operation, the air conditioner (100) may perform the oil recovery operation after receiving approval from an administrator. Here, the administrator may correspond to a person who manages a user account to which the air conditioner (100) is registered. The user account is managed by a server (920), and the air conditioner (100) may be registered to a predetermined user account of the server (920). The administrator may manage the air conditioner (100) by logging into an application of an external device (910) through the user account to which the air conditioner (100) is registered.

[0212] The air conditioner (100) performs oil recovery operation, and if there is an indoor unit (120) that is in an off state, the detection sensor (212) of the indoor unit (120) that is in an off state starts operating in step S504. Next, the air conditioner (100) detects an occupant using the detection value of the detection sensor (212) in step S506.

[0213] If no occupant is detected, the air conditioner (100) can determine in step S1102 whether the administrator has set the operation to perform oil recovery in the absence of the user. Here, absence refers to a case where no occupant is detected in the target space. According to one embodiment of the present disclosure, the administrator can preset whether to perform oil recovery in the absence of the user through an application of an external device (910). The administrator's setting information can be stored in the server (920). In addition, according to one embodiment of the present disclosure, the administrator can preset whether to perform oil recovery in the absence of the user through an input interface (not shown) of the air conditioner (100).

[0214] If the air conditioner (100) is set to perform oil recovery operation in the absence of the manager, the air conditioner (100) can control the expansion valve (216) to be open in step S1110. In this case, the air conditioner (100) can perform oil recovery operation by circulating the two-phase refrigerant by opening the expansion valve (216).

[0215] If the administrator has not set to perform the oil recovery operation in the absence, the air conditioner (100) may output an oil recovery notification in step S1104. For example, the case in which the oil recovery operation is not set to be performed may include a case in which the administrator has not set any setting as to whether to perform the oil recovery operation in the absence. In addition, for example, the case in which the oil recovery operation is not set to be performed may include a case in which the administrator has set not to perform the oil recovery operation in the absence. The oil recovery notification may include a message inquiring whether to perform the oil recovery operation in the indoor unit (120) that is in the off state.

[0216] According to one embodiment of the present disclosure, the air conditioner (100) can output an oil recovery notification through an external device (910) in step S1104. The air conditioner (100) can transmit the oil recovery notification to the external device (910) through the server (910). The external device (910) can output the oil recovery notification through an application.

[0217] Additionally, according to one embodiment of the present disclosure, the air conditioner (100) can output an oil recovery notification inquiring whether to perform oil recovery operation in an indoor unit (120) that is in an off state through at least one output interface (820) among a plurality of indoor units (120).

[0218] If an occupant is detected in step S506, the air conditioner (100) can output an oil recovery notification in step S1104.

[0219] When the external device (910) outputs an oil recovery notification, the external device (910) can receive an input from an administrator who selects whether to perform an oil recovery operation in response to the oil recovery notification. The external device (910) can transmit the administrator's input to the air conditioner (100).

[0220] When the air conditioner (100) outputs an oil recovery notification, the air conditioner (100) can receive input from an administrator or user who selects whether to perform an oil recovery operation in response to the oil recovery notification.

[0221] When an oil recovery notification is output through an external device (910) and an air conditioner (100), the air conditioner (100) can receive a response to the oil recovery notification from either the external device (910) or the air conditioner (100). The air conditioner (100) can give priority to a response to the oil recovery notification that was input first.

[0222] Next, in step S1106, the air conditioner (100) determines whether the administrator has authorized the oil recovery operation in response to the oil recovery notification. The external device (910) or the air conditioner (100) may receive an authorization message from the administrator in response to the oil recovery notification, permitting the oil recovery operation. If the air conditioner (100) receives the authorization message, it determines that the oil recovery operation is authorized.

[0223] If oil recovery operation is permitted, the air conditioner (100) controls the expansion valve (216) to be open in step S1110. In this case, the air conditioner (100) can perform oil recovery operation by circulating the two-phase refrigerant by opening the expansion valve (216).

[0224] If a rejection message not permitting oil recovery operation is received, the air conditioner (100) determines that the oil recovery operation is not permitted in step S1106. If the oil recovery operation is not permitted, the air conditioner (100) may skip the oil recovery operation without performing the oil recovery operation of the indoor unit (120) in the off state in step S1108.

[0225] According to one embodiment of the present disclosure, the manager can individually set whether to perform an oil recovery operation when the user is absent for multiple indoor units (120). For example, the manager can set the first indoor unit (120a) in the living room to perform an oil recovery operation when the user is absent, and the second indoor unit (120b) and the third indoor unit (120c) in the bedroom to not perform an oil recovery operation when the user is absent. The air conditioner (100) can individually perform step S1102 and subsequent steps for each indoor unit (120).

[0226] FIG. 12 is a flowchart illustrating a process for performing oil recovery operation according to one embodiment of the present disclosure.

[0227] According to one embodiment of the present disclosure, the air conditioner (100) can transmit an oil recovery notification to an external device (910) and determine whether to perform an oil recovery operation based on a response to the oil recovery notification.

[0228] The air conditioner (100) can operate the detection sensor (212) of the indoor unit (120) in the off state in step S1202, if at least one indoor unit (120) is in the off state, and if the accumulated operation time reaches the oil recovery cycle in step S1204, in step S1206. The air conditioner (100) can detect an occupant based on the sensor detection value of the detection sensor (212) in step S1208. If an occupant is not detected in the target space of the indoor unit (120) in the off state, the air conditioner (100) determines whether the manager has set whether to perform the oil recovery operation in the absence of an occupant in step S1210.

[0229] If an occupant is detected in step S1208 or if it is not set whether to perform oil recovery operation in the absence of an occupant in step S1210, the air conditioner (100) transmits an oil recovery notification to the server (920) in step S1212. The server (920) transmits an oil recovery notification to an external device (910) logged in with an administrator user account in step S1214.

[0230] The external device (910) receives an administrator's response to the oil recovery notification through the application in step S1216. The administrator's response to the oil recovery notification may include either an authorization message authorizing the oil recovery operation or a rejection message disallowing the oil recovery operation.

[0231] When the external device (910) receives a response to the oil recovery notification, it transmits the response to the oil recovery notification to the server (920) in step S1218. The server (920) transmits the response to the oil recovery notification to the air conditioner (100) in step S1220.

[0232] When the air conditioner (100) receives a response to the oil recovery notification, in step S1222, it determines whether the administrator has permitted the oil recovery operation. If the administrator has permitted the oil recovery operation, the air conditioner (100) controls the expansion valve (216) of the indoor unit (120) to be open in step S1224. If the administrator has permitted the oil recovery operation, the air conditioner (100) controls the expansion valve (216) of the indoor unit (120) to be closed in step S1226, thereby skipping the oil recovery operation.

[0233] A device-readable storage medium may be provided in the form of a non-transitory storage medium. Here, the term "non-transitory storage medium" simply means a tangible device that does not contain signals (e.g., electromagnetic waves). This term does not distinguish between cases where data is permanently stored in the storage medium and cases where data is temporarily stored. For example, a "non-transitory storage medium" may include a buffer in which data is temporarily stored.

[0234] According to one embodiment, the method according to various embodiments disclosed in the present document may be provided as included in a computer program product. The computer program product may be traded as a product between a seller and a buyer. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., compact disc read-only memory (CD-ROM)), or may be distributed online (e.g., downloaded or uploaded) through an application store or directly between two user devices (e.g., smartphones). In the case of online distribution, at least a portion of the computer program product (e.g., a downloadable app) may be temporarily stored or temporarily generated in a machine-readable storage medium, such as the memory of a manufacturer's server, an application store's server, or an intermediary server.

[0235] According to one aspect of one embodiment of the present disclosure, an air conditioner is provided. The air conditioner may include a plurality of indoor units, an outdoor unit including a condenser and a compressor, a memory storing at least one instruction, and at least one processor. Each of the plurality of indoor units may include an expansion valve, an evaporator, and a detection sensor. The at least one processor may execute at least one instruction to perform an oil recovery operation for recovering oil using a compressor, and while performing the oil recovery operation, if there is an indoor unit that is turned off among the plurality of indoor units, detect an occupant of a target space using a detection sensor of the indoor unit in the off state, and while performing the oil recovery operation, control an open state of an expansion valve of the indoor unit in the off state based on a result of detecting an occupant of the indoor unit in the off state.

[0236] Additionally, according to one embodiment of the present disclosure, at least one processor can control an expansion valve of an indoor unit in an off state to be closed when an occupant is present within a first distance from the indoor unit in an off state while performing an oil recovery operation by executing at least one instruction.

[0237] In addition, according to one embodiment of the present disclosure, the at least one processor can control the open state of the expansion valve of the indoor unit in the off state to the maximum open state when no occupant is present in the target space of the indoor unit in the off state while performing an oil recovery operation by executing at least one instruction.

[0238] Additionally, according to one embodiment of the present disclosure, at least one processor may, by executing at least one instruction, increase the opening step of the expansion valve as the distance from the indoor unit in the off state to the occupant increases when the occupant is located further than a first distance from the indoor unit in the off state while performing an oil recovery operation.

[0239] Additionally, according to one embodiment of the present disclosure, at least one processor can control the open step of the expansion valve of the indoor unit in the powered-on operating state to the maximum open state while performing the oil recovery operation by executing at least one instruction.

[0240] Additionally, according to one embodiment of the present disclosure, the air conditioner includes an output interface, and at least one processor can output a message indicating that the oil recovery operation is being performed through the output interface while performing the oil recovery operation by executing the at least one instruction.

[0241] Additionally, according to one embodiment of the present disclosure, at least one processor can perform an oil recovery operation whenever the cumulative operation time of the outdoor unit reaches the oil recovery cycle by executing at least one instruction.

[0242] In addition, according to one embodiment of the present disclosure, the air conditioner further includes a communication module, and at least one processor, by executing at least one instruction, detects an occupant of a target space using a detection sensor of an indoor unit in an off state when starting an oil recovery operation, and when an occupant is detected in the target space, transmits an oil recovery notification to an external device of a manager of the air conditioner through the communication module, and when a permission message permitting an oil recovery operation is received from the external device, controls an expansion valve (216) of the indoor unit in an off state to an open state, and when a rejection message not permitting an oil recovery operation is received from the external device, controls the expansion valve of the indoor unit in an off state to a closed state.

[0243] In addition, according to one embodiment of the present disclosure, at least one processor may, by executing at least one instruction, detect an occupant of a target space using a detection sensor of an indoor unit in an off state when starting an oil recovery operation, determine whether an occupant is set to perform an oil recovery operation in the absence of the occupant when no occupant is detected in the target space, and, if the oil recovery operation in the absence of the occupant is set to be performed, control an expansion valve of the indoor unit to an open state.

[0244] In addition, according to one embodiment of the present disclosure, the air conditioner may further include a communication module. At least one processor, by executing at least one instruction, if the air conditioner is not set to perform an oil recovery operation in absence, transmits an oil recovery notification to an external device of a manager of the air conditioner through the communication module, and if a permission message permitting an oil recovery operation is received from the external device, controls an expansion valve of an indoor unit in an off state to an open state, and if a rejection message not permitting an oil recovery operation is received from the external device, controls an expansion valve of an indoor unit in an off state to a closed state.

[0245] Additionally, according to one embodiment of the present disclosure, at least one processor can control the expansion valve of each of the plurality of indoor units to be closed when the oil recovery operation is terminated by executing at least one instruction.

[0246] In addition, according to one aspect of one embodiment of the present disclosure, a method for controlling an air conditioner is provided. The air conditioner may include a plurality of indoor units and an outdoor unit, the outdoor unit may include a condenser and a compressor, and each of the plurality of indoor units may include an expansion valve, an evaporator, and a detection sensor. The method for controlling the air conditioner may include a step of performing an oil recovery operation for recovering oil by a compressor, a step of detecting an occupant of a target space using a detection sensor of an indoor unit in the off state when an indoor unit in an off state with its power turned off exists among the plurality of indoor units during the oil recovery operation, and a step of controlling an open state of an expansion valve of the indoor unit in the off state based on a result of detecting an occupant of the indoor unit in the off state during the oil recovery operation.

[0247] Additionally, according to one embodiment of the present disclosure, the step of controlling the open state of the expansion valve of the indoor unit in the off state may include the step of controlling the expansion valve of the indoor unit in the off state to the closed state when an occupant is present within a first distance from the indoor unit in the off state while performing an oil recovery operation.

[0248] In addition, according to one embodiment of the present disclosure, the step of controlling the open state of the expansion valve of the indoor unit in the off state may include a step of controlling the open state of the expansion valve of the indoor unit in the off state to the maximum open state when no occupant is present in the target space of the indoor unit in the off state while performing an oil recovery operation.

[0249] Additionally, according to one embodiment of the present disclosure, the step of controlling the open state of the expansion valve of the indoor unit in the off state may include a step of increasing the open step of the expansion valve as the distance from the indoor unit in the off state to the occupant increases, when the occupant is located further than a first distance from the indoor unit in the off state while performing an oil recovery operation.

[0250] In addition, according to one embodiment of the present disclosure, the air conditioner control method may further include a step of controlling the open step of an expansion valve of an indoor unit in an operating state with power turned on to a maximum open state while performing an oil recovery operation.

[0251] Additionally, according to one embodiment of the present disclosure, the air conditioner control method may further include a step of outputting a message indicating that the oil recovery operation is being performed through an output interface of the air conditioner during the oil recovery operation.

[0252] Additionally, according to one embodiment of the present disclosure, the step of performing oil recovery operation may be performed whenever the cumulative operation time of the outdoor unit reaches the oil recovery cycle.

[0253] In addition, according to one aspect of one embodiment of the present disclosure, a computer-readable recording medium having recorded thereon a program for performing an air conditioner control method according to one embodiment of the present disclosure on a computer is provided.

Claims

1. In the air conditioner (100), Multiple indoor units (120, 120a, 120b, 120c); An outdoor unit (110) including a condenser and a compressor; a memory (214) storing at least one instruction; and comprising at least one processor (210), Each of the above multiple indoor units (120, 120a, 120b, 120c) includes an expansion valve (216), an evaporator (218), and a detection sensor (212). The at least one processor (210) executes the at least one instruction, Perform oil recovery operation to recover oil using the above compressor (222), During the above oil recovery operation, if there is an indoor unit (120, 120a, 120b, 120c) that is turned off among the plurality of indoor units (120, 120a, 120b, 120c), the presence of an occupant in the target space is detected using the detection sensor (212) of the indoor unit (120, 120a, 120b, 120c) that is turned off, An air conditioner (100) that controls the open state of the expansion valve (216) of the indoor unit (120, 120a, 120b, 120c) in the off state based on the result of detecting occupancy of the indoor unit (120, 120a, 120b, 120c) in the off state while performing the above oil recovery operation.

2. In paragraph 1, The at least one processor (210) executes the at least one instruction, An air conditioner (100) that controls the expansion valve (216) of the indoor unit (120, 120a, 120b, 120c) in the off state to be closed when an occupant is present within a first distance from the indoor unit (120, 120a, 120b, 120c) in the off state while performing the above oil recovery operation.

3. In any one of paragraphs 1 and 2, The at least one processor (210) executes the at least one instruction, An air conditioner (100) that controls the open state of the expansion valve (216) of the indoor unit (120, 120a, 120b, 120c) in the off state to the maximum open state when no occupant is present in the target space of the indoor unit (120, 120a, 120b, 120c) in the off state while performing the above oil recovery operation.

4. In any one of paragraphs 1 to 3, The at least one processor (210) executes the at least one instruction, An air conditioner (100) in which, while performing the above oil recovery operation, when an occupant is located further than a first distance from the indoor unit (120, 120a, 120b, 120c) in the off state, the open step of the expansion valve (216) is increased as the distance from the indoor unit (120, 120a, 120b, 120c) in the off state to the occupant increases.

5. In any one of paragraphs 1 to 4, The at least one processor (210) executes the at least one instruction, An air conditioner (100) that controls the open step of the expansion valve (216) of the indoor unit (120, 120a, 120b, 120c) in the operating state with the power turned on to the maximum open state while performing the above oil recovery operation.

6. In any one of paragraphs 1 to 5, The above air conditioner (100) includes an output interface (820), The at least one processor (210) executes the at least one instruction, An air conditioner (100) that outputs a message indicating that the oil recovery operation is being performed through the output interface (820) during the above oil recovery operation.

7. In any one of paragraphs 1 to 6, The at least one processor (210) executes the at least one instruction, An air conditioner (100) that performs the oil recovery operation whenever the cumulative operation time of the outdoor unit (110) reaches the oil recovery cycle.

8. In any one of paragraphs 1 to 7, The above air conditioner (100) further includes a communication module (810), The at least one processor (210) executes the at least one instruction, When the above oil recovery operation starts, the presence of an occupant in the target space is detected using the detection sensor (212) of the indoor unit (120, 120a, 120b, 120c) in the off state, When an occupant is detected in the above target space, an oil recovery notification is sent to the external device (910) of the manager of the air conditioner (100) through the communication module (810). When a permission message permitting the oil recovery operation is received from the external device (910), the expansion valve (216) of the indoor unit (120, 120a, 120b, 120c) in the off state is controlled to the open state, An air conditioner (100) that controls the expansion valve (216) of the indoor unit (120, 120a, 120b, 120c) in the off state to be closed when a rejection message that does not permit the oil recovery operation is received from the external device (910).

9. In any one of paragraphs 1 to 8, The at least one processor (210) executes the at least one instruction, When the above oil recovery operation starts, the presence of an occupant in the target space is detected using the detection sensor (212) of the indoor unit (120, 120a, 120b, 120c) in the off state, If no occupant is detected in the above target space, determine whether the oil recovery operation is set to be performed in absence, An air conditioner (100) that controls the expansion valve (216) of the indoor unit (120, 120a, 120b, 120c) to be open when the oil recovery operation is set to be performed in absence.

10. In paragraph 9, The above air conditioner (100) further includes a communication module (810), The at least one processor (210) executes the at least one instruction, If the oil recovery operation is not set to be performed in absence, an oil recovery notification is transmitted to the external device (910) of the manager of the air conditioner (100) through the communication module (810), When a permission message permitting the oil recovery operation is received from the external device (910), the expansion valve (216) of the indoor unit in the off state is controlled to the open state, An air conditioner (100) that controls the expansion valve (216) of the indoor unit (120, 120a, 120b, 120c) in the off state to be closed when a rejection message that does not permit the oil recovery operation is received from the external device (910).

11. In any one of paragraphs 1 to 10, The above air conditioner (100) further includes a communication module (810), The at least one processor (210) executes the at least one instruction, An air conditioner (100) that transmits a message indicating that the oil recovery operation is being performed to an external device (910) through the communication module (810) during the performance of the above oil recovery operation.

12. In any one of paragraphs 1 to 11, The at least one processor (210) executes the at least one instruction, An air conditioner (100) that controls the expansion valve (216) of each of the plurality of indoor units (120, 120a, 120b, 120c) to be closed when the above oil recovery operation is completed.

13. In a method for controlling an air conditioner, The above air conditioner includes a plurality of indoor units and outdoor units, The above outdoor unit includes a condenser and a compressor, Each of the above multiple indoor units includes an expansion valve, an evaporator, and a detection sensor, The above air conditioner control method is, A step of performing an oil recovery operation to recover oil using the compressor; During the above oil recovery operation, if there is an indoor unit in an off state with the power turned off among the plurality of indoor units, a step of detecting an occupant in the target space using a detection sensor of the indoor unit in the off state; and An air conditioner control method, comprising a step of controlling the open state of an expansion valve of an indoor unit in an off state based on a result of detecting an occupant of the indoor unit in an off state while performing the oil recovery operation.

14. In paragraph 13, The step of controlling the open state of the expansion valve of the indoor unit in the above off state is: An air conditioner control method, comprising the step of controlling an expansion valve of an indoor unit in an off state to a closed state when an occupant is present within a first distance from the indoor unit in an off state while performing the oil recovery operation.

15. A computer-readable recording medium having recorded thereon a program for performing the method of any one of claims 13 to 14 on a computer.

Images