Air conditioner and multi air conditioner having same

Abstract

This air conditioner comprises: an outdoor unit; an indoor unit which includes a detector for detecting if there are refrigerant leaks and which is connected to the outdoor unit; a high-pressure gas pipe for supplying refrigerant from the outdoor unit to the indoor unit; a low-pressure gas pipe for returning the refrigerant from the indoor unit to the outdoor unit; a liquid pipe for supplying the refrigerant from the outdoor unit to the indoor unit or returning the refrigerant from the indoor unit to the outdoor unit; an opening / closing valve for opening and closing the high-pressure gas pipe, the low-pressure gas pipe, and the liquid pipe; and a control unit, which is electrically connected to the detector and the opening / closing valve, for controlling the opening / closing valve on the basis of the detector having detected a refrigerant leak, so as to return the refrigerant from the indoor unit to the outdoor unit through the low-pressure gas pipe.

Description

Air conditioner and multi-air conditioner including same

[0001] The present disclosure relates to an air conditioner including a control unit for opening and closing a refrigerant pipe and a multi-air conditioner including the same.

[0002] An air conditioner is a device used to cool or heat an indoor space. If the indoor space is divided into multiple spaces, an air conditioner may be installed to cool or heat each space.

[0003] A multi-air conditioner can have multiple indoor units connected to a single outdoor unit. One outdoor unit can be connected to multiple indoor units via refrigerant pipes. A valve is positioned on the refrigerant pipes to open and close the refrigerant pipes. The valve is electrically connected to the control unit and can be controlled to open and close the refrigerant pipes.

[0004] Multiple indoor units can be installed in each indoor space, allowing the temperature of each space to be individually controlled according to the user's convenience. That is, as the control unit controls the on / off valves, the multiple indoor units operate in either cooling or heating mode, allowing the installed indoor spaces to be individually cooled or heated.

[0005] One aspect of the present disclosure provides an air conditioner with improved safety in use and a multi-air conditioner including the same.

[0006] One aspect of the present disclosure provides an air conditioner and a multi-air conditioner including the same, which are arranged to block the flow of refrigerant toward the indoor unit when the refrigerant leaks.

[0007] One aspect of the present disclosure provides an air conditioner configured to recover residual refrigerant to an outdoor unit when refrigerant leaks, and a multi-air conditioner including the same.

[0008] The technical problems to be achieved in this document are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0009] An air conditioner according to the invention includes an outdoor unit, a detector for detecting a refrigerant leak, and an indoor unit connected to the outdoor unit. The air conditioner includes a high-pressure gas pipe for supplying refrigerant from the outdoor unit to the indoor unit. The air conditioner includes a low-pressure gas pipe for recovering refrigerant from the indoor unit to the outdoor unit. The air conditioner includes a liquid pipe for supplying refrigerant from the outdoor unit to the indoor unit or recovering refrigerant from the indoor unit to the outdoor unit. The air conditioner includes an on-off valve for opening and closing the high-pressure gas pipe, the low-pressure gas pipe, and the liquid pipe. The air conditioner includes a control unit electrically connected to the detector and the on-off valve. The control unit controls the on-off valve to recover refrigerant from the indoor unit to the outdoor unit through the low-pressure gas pipe based on detection of a refrigerant leak by the detector.

[0010] A multi-air conditioner according to the invention comprises an outdoor unit, a first indoor unit and a second indoor unit, each of which includes a detector for detecting a refrigerant leak and is spaced apart from each other and connected to the outdoor unit, respectively. The multi-air conditioner comprises a heating and cooling switching device including a control unit for controlling the first indoor unit and the second indoor unit so that the first and second indoor units operate in a cooling or heating mode. The heating and cooling switching device includes a high-pressure gas pipe provided to supply refrigerant from the outdoor unit to the first indoor unit or the second indoor unit. The heating and cooling switching device includes a low-pressure gas pipe provided to recover refrigerant from the first or the second indoor unit to the outdoor unit. The heating and cooling switching device includes a liquid pipe provided to supply refrigerant from the outdoor unit to the first or the second indoor unit or to recover refrigerant from the first or the second indoor unit to the outdoor unit. The above-mentioned heating and cooling switching device includes an on-off valve configured to open and close the high-pressure gas pipe, the low-pressure gas pipe, and the liquid pipe. The control unit controls the on-off valve so that refrigerant is recovered from the first indoor unit or the second indoor unit to the outdoor unit through the low-pressure gas pipe based on the detection of a refrigerant leak by the detector.

[0011] An air conditioner according to the invention includes an outdoor unit including a compressor that compresses and discharges a refrigerant. The air conditioner includes a detector that detects a refrigerant leak and an indoor unit connected to the outdoor unit. The air conditioner includes a high-pressure gas pipe connecting the compressor and the indoor unit so that the refrigerant discharged from the compressor is supplied to the indoor unit. The air conditioner includes a low-pressure gas pipe provided to recover refrigerant from the indoor unit to the compressor. The air conditioner includes a liquid pipe provided to supply refrigerant from the outdoor unit to the indoor unit or to recover refrigerant from the indoor unit to the outdoor unit. The air conditioner includes an on-off valve provided to open and close the high-pressure gas pipe, the low-pressure gas pipe, and the liquid pipe. The air conditioner includes a control unit that is electrically connected to the detector and the on-off valve, and controls the on-off valve so that refrigerant from the indoor unit is recovered to the compressor based on the detector detecting a refrigerant leak.

[0012] Figure 1 is a schematic drawing of an air conditioner according to one embodiment.

[0013] Figure 2 is a schematic drawing showing the state in which the pressure reducing valve opens and refrigerant flows in the pressure reducing tube when the indoor unit of Figure 1 switches from heating mode to cooling mode.

[0014] Figure 3 is a schematic drawing showing the indoor unit of Figure 1 operating in cooling mode.

[0015] FIG. 4 is a drawing illustrating a state in which a control unit controls a liquid pipe valve to close a liquid pipe and block the flow of refrigerant toward the indoor unit when a detector detects a refrigerant leak while the indoor unit of an air conditioner is operating in cooling mode according to one embodiment.

[0016] FIG. 5 is a drawing illustrating a state in which the control unit controls the low-pressure valve to close the low-pressure gas pipe and the connection pipe valve to close the connection pipe when the indoor unit side refrigerant in FIG. 4 is returned to the outdoor unit through the low-pressure gas pipe and the refrigerant leakage is not detected by the detector.

[0017] FIG. 6 is a drawing illustrating a state in which, when a detector detects a refrigerant leak while the indoor unit of an air conditioner is operating in heating mode according to one embodiment, the control unit controls a high-pressure valve to close a high-pressure gas pipe to block the flow of refrigerant toward the indoor unit, controls a low-pressure valve to open a low-pressure gas pipe to allow the refrigerant to be returned to the outdoor unit, and controls a liquid pipe valve to close a liquid pipe.

[0018] FIG. 7 is a drawing illustrating a state in which the control unit controls the low-pressure valve to close the low-pressure gas pipe and the connection pipe valve to close the connection pipe when the indoor unit side refrigerant in FIG. 6 is returned to the outdoor unit through the low-pressure gas pipe and the detector does not detect a refrigerant leak.

[0019] Fig. 8 is a schematic diagram illustrating the structure of a multi-air conditioner according to one embodiment.

[0020] FIG. 9 is a drawing showing an enlarged view of a part of a cooling / heating switching device and an indoor unit of a multi-air conditioner according to one embodiment, and showing a state in which a control unit controls a first liquid pipe valve to block the flow of refrigerant toward the first indoor unit by closing a first liquid pipe connected to the first indoor unit when a first detector detects a refrigerant leak while the first indoor unit is operating in cooling mode.

[0021] FIG. 10 is a drawing illustrating a state in which, when the refrigerant on the first indoor unit side in FIG. 9 is recovered to the outdoor unit through the first low-pressure gas pipe and no refrigerant leakage is detected by the first detector, the control unit controls the first low-pressure valve to close the first low-pressure gas pipe and controls the first connection pipe valve to close the first connection pipe.

[0022] FIG. 11 is a drawing showing an enlarged view of a part of a heating / cooling switching device and an indoor unit of a multi-air conditioner according to one embodiment, and when a first detector detects a refrigerant leak while the first indoor unit is operating in heating mode, the control unit controls the first high-pressure valve to close the first high-pressure gas pipe to block the flow of refrigerant toward the first indoor unit, controls the first low-pressure valve to open the first low-pressure gas pipe to return the refrigerant to the outdoor unit, and controls the first liquid pipe valve to close the first liquid pipe.

[0023] FIG. 12 is a drawing illustrating a state in which the control unit controls the first low-pressure valve to close the first low-pressure gas pipe and the first connection pipe valve to close the first connection pipe when the refrigerant on the first indoor unit side of FIG. 11 is recovered to the outdoor unit through the first low-pressure gas pipe and no refrigerant leakage is detected by the first detector.

[0024] Fig. 13 is a control block diagram for explaining an air conditioner according to one embodiment.

[0025] Fig. 14 is a flowchart showing a method for a control unit to control an opening / closing valve according to a refrigerant leak when an air conditioner according to one embodiment is in cooling mode.

[0026] Fig. 15 is a flowchart showing a method for a control unit to control an opening / closing valve according to a refrigerant leak when an air conditioner according to one embodiment is in heating mode.

[0027] Fig. 16 is a flowchart showing a method for a control unit to control an opening / closing valve according to a refrigerant leak when an air conditioner according to one embodiment is not operating.

[0028] Fig. 17 is a flowchart showing a method for controlling a connecting pipe valve when a refrigerant leak occurs in an air conditioner according to one embodiment.

[0029] Fig. 18 is a flowchart showing a method for controlling a pressure reducing valve when a refrigerant leak occurs in an air conditioner according to one embodiment.

[0030] 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 include various modifications, equivalents, or substitutes of the embodiments.

[0031] In connection with the description of the drawings, similar reference numerals may be used for similar or related components.

[0032] 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.

[0033] 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.

[0034] The term "and / or" includes any combination of a plurality of related described elements or any one of a plurality of related described elements.

[0035] 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).

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] An air conditioner according to various embodiments 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.

[0041] In one embodiment, 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 stand-alone air conditioner, and a system air conditioner.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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, it releases heat to the outdoor air, and while the refrigerant flowing in the outdoor heat exchanger evaporates, it absorbs heat from the outdoor air.

[0046] 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.

[0047] 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. The cooled indoor air can then be blown through the cooled indoor heat exchanger, thereby cooling the room. Furthermore, while the refrigerant condenses in the indoor heat exchanger, the refrigerant can release heat to the indoor air. By blowing the heated indoor air through the high-temperature indoor heat exchanger, the room can be heated.

[0048] 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.

[0049] The refrigerant may circulate through the refrigerant pipe 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] Multiple outdoor units may all 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.

[0055] 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.

[0056] 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.

[0057] The air conditioner may further include a flow diverter valve positioned along 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 indoor unit's operating mode (e.g., cooling operation or heating operation). The flow diverter valve may be connected to the discharge port of the compressor.

[0058] 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.

[0059] 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.

[0060] An outdoor fan may be installed near 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] The housing may include an intake port through which indoor air may be drawn into the interior of the housing.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] Blowers may include indoor fans and fan motors. For example, indoor fans may include axial fans, diffusion fans, crossflow fans, and centrifugal fans.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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 a wireless remote controller. The configuration data input through the wireless remote controller may be transmitted to the input interface as an infrared signal.

[0074] 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.

[0075] 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 the components of the indoor unit.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] The long-distance communication module may include a communication module that performs various types of long-distance 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.

[0081] 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.

[0082] The outdoor unit control unit can be electrically connected to components of the outdoor unit and can 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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 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 nonvolatile memory, such as Read Only Memory (ROM), Erasable Programmable Read Only Memory (EPROM), and Electrically Erasable Programmable Read Only Memory (EEPROM), for storing data for a long period of time.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] Hereinafter, with reference to the attached drawings, an air conditioner according to various embodiments and a multi-air conditioner including the same will be specifically described.

[0092] Fig. 1 is a schematic drawing of an air conditioner according to one embodiment. Fig. 2 is a schematic drawing of a pressure reducing valve opening and refrigerant flowing through a pressure reducing tube when the indoor unit of Fig. 1 switches from heating mode to cooling mode. Fig. 3 is a schematic drawing of the indoor unit of Fig. 1 switching to cooling mode and operating.

[0093] Referring to FIGS. 1 to 3, the air conditioner (1) may include an outdoor unit (10). The outdoor unit (10) may be installed on the outdoor side.

[0094] The air conditioner (1) may include an indoor unit (40A). The indoor unit (40A) may be installed on the indoor side where occupancy is required.

[0095] The indoor unit (40A) may include an indoor heat exchanger (42A). The indoor heat exchanger (42A) may be provided so that the refrigerant passing through the indoor heat exchanger (42A) undergoes heat exchange.

[0096] The indoor unit (40A) may include an indoor blower fan (41A). The indoor blower fan (41A) may be installed on the indoor heat exchanger (42A) side. The indoor blower fan (41A) may blow air from the indoor heat exchanger (42A) side to a room where refrigeration is required after heat exchange of the refrigerant occurs in the indoor heat exchanger (42A).

[0097] An air conditioner (1) may include a refrigerant pipe (20). The refrigerant pipe (20) may be provided to connect an outdoor unit (10) and an indoor unit (40A) to allow refrigerant to flow. That is, the refrigerant may be supplied to the indoor unit (40A) through the refrigerant pipe (20) and returned to the outdoor unit (10) to circulate.

[0098] The air conditioner (1) may include an on-off valve (200) configured to open and close a refrigerant pipe (20). Depending on the operation of the on-off valve (200), the refrigerant pipe (20) is opened and closed, thereby controlling the flow of refrigerant flowing in the refrigerant pipe (20).

[0099] The refrigerant pipe (20) may include a high-pressure gas pipe (21) that is provided to supply refrigerant from the outdoor unit (10) to the indoor unit (40A). The high-pressure gas pipe (21) may connect the outdoor unit (10) and the indoor unit (40A) to supply high-temperature, high-pressure refrigerant from the outdoor unit (10) to the indoor unit (40A).

[0100] The on-off valve (200) may include a high-pressure valve (212) configured to open and close a high-pressure gas pipe (21). The high-pressure valve (212) may be placed in the high-pressure gas pipe (21). When the high-pressure valve (212) is closed, the high-pressure gas pipe (21) is blocked, and refrigerant may not flow in the high-pressure gas pipe (21).

[0101] The refrigerant pipe (20) may include a low-pressure gas pipe (22) provided to recover refrigerant from the indoor unit (40A) to the outdoor unit (10). The low-pressure gas pipe (22) may connect the indoor unit (40A) and the outdoor unit (10) to recover refrigerant in a low-temperature, low-pressure state from the indoor unit (40A) to the outdoor unit (10).

[0102] The on-off valve (200) may include a low-pressure valve (222). The low-pressure valve (222) may be placed in the low-pressure gas pipe (22). When the low-pressure valve (222) is closed, the low-pressure gas pipe (22) is blocked, so that refrigerant may not flow in the low-pressure gas pipe (22).

[0103] A check valve (223) may be arranged in the low-pressure gas pipe (22). The check valve (223) may be arranged upstream of the low-pressure valve (222) with respect to the flow direction of the refrigerant in the low-pressure gas pipe (22). The refrigerant may flow from the indoor unit (40A) to the outdoor unit (10) through the low-pressure gas pipe (22). The check valve (223) may be installed to prevent the refrigerant flowing in the low-pressure gas pipe (22) from flowing from the outdoor unit (10) to the indoor unit (40A). Therefore, the check valve (223) may prevent the refrigerant in the low-pressure gas pipe (22) from flowing backward and control the flow of the refrigerant so that the refrigerant on the indoor unit (40A) side is recovered to the outdoor unit (10).

[0104] The refrigerant pipe (20) may include a liquid pipe (23). The liquid pipe (23) may be provided to connect the indoor unit (40A) and the outdoor unit (10). The liquid pipe (23) may be provided to supply refrigerant from the outdoor unit (10) to the indoor unit (40A). The liquid pipe (23) may be provided to recover refrigerant from the indoor unit (40A) to the outdoor unit (10). A liquid refrigerant may flow in the liquid pipe (23).

[0105] The on-off valve (200) may include a liquid pipe valve (232). The liquid pipe valve (232) may be provided in the liquid pipe (23). When the liquid pipe valve (232) is closed, the liquid pipe (23) is blocked, so that refrigerant may not flow in the liquid pipe (23).

[0106] The refrigerant pipe (20) may include a pressure reducing pipe (241). The pressure reducing pipe (241) may be arranged to be combined with a low-pressure gas pipe (22). The pressure reducing pipe (241) may be combined with the low-pressure gas pipe (22) so as to connect the upstream and downstream of the low-pressure gas pipe (22) with respect to the flow direction of the refrigerant in the low-pressure gas pipe (22) based on the low-pressure valve (222).

[0107] More specifically, one end (2411) of the pressure reducing tube (241) can be connected upstream of the low-pressure valve (222) with respect to the flow direction of the refrigerant in the low-pressure gas tube (22). And, the other end (2412) of the pressure reducing tube (241) can be connected downstream of the low-pressure valve (222) with respect to the flow direction of the refrigerant in the low-pressure gas tube (22).

[0108] The check valve (223) can be installed upstream of one end (2411) of the pressure reducing pipe (241) with respect to the flow direction of the refrigerant in the low-pressure gas pipe (22). Therefore, the check valve (223) can prevent the phenomenon of the refrigerant flowing in the pressure reducing pipe (241) from flowing backward toward the indoor unit (40A).

[0109] The on-off valve (200) may include a pressure reducing valve (242). The pressure reducing valve (242) may be arranged in the pressure reducing tube (241) to open and close the pressure reducing tube (241). Depending on whether the pressure reducing valve (242) is operated, the flow of refrigerant in the pressure reducing tube (241) may be controlled.

[0110] The outdoor unit (10) may include a compressor (11A, 11B). The compressor (11A, 11B) may compress a refrigerant. The refrigerant compressed by passing through the compressor (11A, 11B) may be in a high-temperature, high-pressure gaseous state.

[0111] The outdoor unit (10) may include a four-way valve (13). The four-way valve (13) may be arranged on the discharge side of the compressor (11A, 11B) to switch the refrigerant flow path between heating operation and cooling operation.

[0112] The outdoor unit (10) may include an outdoor heat exchanger (15). The outdoor heat exchanger (15) may be arranged on one side of the compressor (11A, 11B) to change the state of the refrigerant through heat exchange.

[0113] The outdoor unit (10) may include an outdoor blower fan (16). The outdoor blower fan (16) may be installed on the outdoor heat exchanger (15) side. The outdoor blower fan (16) may be installed so that air from the outdoor heat exchanger (15) side is discharged to the outside.

[0114] The outdoor unit (10) may include an outdoor expansion valve (17A). The outdoor expansion valve (17A) may be arranged on one side of the outdoor heat exchanger (15). The outdoor heat exchanger (15) may be configured to depressurize and expand the refrigerant.

[0115] The outdoor unit (10) may include an accumulator (19). The accumulator (19) may be provided on one side of the compressor (11A, 11B). The accumulator (19) may be arranged so that gaseous refrigerant is sucked into the compressor (11A, 11B).

[0116] The four-way valve (13) may include a first port (13A). The outdoor unit (10) may include an oil separator (12). The four-way valve (13) of the outdoor unit (10) may be arranged so that the first port (13A) is connected to the discharge port of the compressor (11A, 11B) through the oil separator (12). The refrigerant passing through the compressor (11A, 11B) may pass through the oil separator (12) and connect to the four-way valve (13).

[0117] *The 1004-room valve (13) may include a second port (13B). The outdoor unit (10) may include a receiver tank (18). The second port (13B) may be provided to communicate with the outdoor heat exchanger (15), the outdoor expansion valve (17A), and the receiver tank (18). The second port (13B) may be provided to be connected to the liquid pipe (23) through the outdoor heat exchanger (15), the outdoor expansion valve (17A), and the receiver tank (18).

[0118] The outdoor unit (10) may include a high-pressure branch pipe (14). The high-pressure branch pipe (14) may be provided to be connected to a second port (13B). The high-pressure branch pipe (14) may be branched between the second port (13B) of the four-way valve (13) and the outdoor heat exchanger (15). The high-pressure branch pipe (14) may be branched between the second port (13B) and the liquid pipe (23). The high-pressure branch pipe (14) may be connected to a high-pressure gas pipe (21). The outdoor unit (10) may include a solenoid valve (14A). The outdoor unit (10) may include a check valve (14B) to prevent backflow of the refrigerant. The solenoid valve (14A) and the check valve (14B) may be arranged in the high-pressure branch pipe (14). The second port (13B) can be connected to the high pressure branch pipe (14) through an electronic valve (14A).

[0119] The four-way valve (13) may include a third port (13C). The third port (13C) may be connected to a low-pressure gas pipe (22). The third port (13C) may branch to an accumulator (19) before being connected to the low-pressure gas pipe (22). That is, the third port (13C) may be connected to the low-pressure gas pipe (22) on the downstream side of the accumulator (19). The third port (13C) may be arranged so that the refrigerant circulates to the compressor (11A, 11B) via the third port (13C) and the accumulator (19).

[0120] The four-way valve (13) may include a fourth port (13D). The fourth port (13D) may be connected to a high-pressure gas pipe (21).

[0121] The refrigerant pipe (20) may include a gas pipe connecting pipe (261). The gas pipe connecting pipe (261) may connect the high-pressure gas pipe (21) to the indoor unit (40A). The gas pipe connecting pipe (261) may connect the low-pressure gas pipe (22) to the indoor unit (40A). One end of the gas pipe connecting pipe (261) may be joined to the high-pressure gas pipe (21). One end of the gas pipe connecting pipe (261) may be joined to the low-pressure gas pipe (22). The other end of the gas pipe connecting pipe (261) may be connected to the indoor unit (40A).

[0122] The refrigerant pipe (20) may include a connecting pipe (43A). The connecting pipe (43A) may connect the liquid pipe (23) and the indoor unit (40A). More specifically, the connecting pipe (43A) may connect the liquid pipe (23) and the heat exchanger (42) of the indoor unit. The connecting pipe (43A) may include one end connected to the liquid pipe (23) and the other end connected to the heat exchanger (42) of the indoor unit.

[0123] One end of the connecting pipe (43A) can be joined to the liquid pipe (23). The other end of the connecting pipe (43A) can be connected to the heat exchanger (42) of the indoor unit.

[0124] The on-off valve (200) may include a connection pipe valve (44A) arranged in the connection pipe (43A). Based on the operation of the connection pipe valve (44A), the flow of refrigerant in the connection pipe (43A) can be controlled.

[0125] When the indoor unit (40A) is in heating operation, the refrigerant may be in a high-temperature, high-pressure gaseous state as it passes through the compressor (11A, 11B). Thereafter, the refrigerant may flow into the high-pressure gas pipe (21) through the fourth port of the four-way valve (13). At this time, the high-pressure valve (212) may be in an open state. The refrigerant that has flowed into the high-pressure gas pipe (21) may flow into the indoor unit (40A) through the gas pipe connection pipe (261). At this time, since the low-pressure valve (222) is in a closed state, the refrigerant may flow into the indoor unit (40A). The refrigerant that has flowed into the indoor unit (40A) may change into a high-temperature, high-pressure liquid state through heat exchange with the indoor heat exchanger (42A). After the heat exchange, the indoor blower fan (41A) may blow air from the indoor heat exchanger (42A) side into the occupied space to heat the occupied space. The refrigerant that has passed through the indoor heat exchanger (42A) can flow into the connecting pipe (43A). At this time, the connecting pipe valve (44A) may be in an open state. The refrigerant that has flowed into the connecting pipe (43A) can flow into the outdoor expansion valve (17A) through the liquid pipe (23). At this time, the liquid pipe valve (232) may be in an open state. The refrigerant can change into a low-temperature, low-pressure liquid state while passing through the outdoor expansion valve (17A). Thereafter, the refrigerant can flow into the outdoor heat exchanger (15). The refrigerant that has passed through the outdoor heat exchanger (15) can be in a low-temperature, low-pressure gaseous state. Thereafter, the refrigerant can flow into the second port (13B) of the four-way valve (13) and then into the accumulator (19) through the third port (13C). The refrigerant flowing into the accumulator (19) can flow again into the compressor (11A, 11B) and be compressed to change into a high-temperature, high-pressure gaseous state. This can be referred to as a heating cycle or heating mode.

[0126] An air conditioner (1) in heating operation can switch to cooling operation. When the air conditioner (1) in heating operation switches to cooling operation, the high-pressure gas pipe (21) may be closed and the low-pressure gas pipe (22) may be opened. At this time, since the refrigerant is flowing in the high-pressure gas pipe (21), high-pressure refrigerant may exist in the low-pressure gas pipe (22) on the side where the low-pressure valve (222) is arranged in contact with the high-pressure gas pipe (21). In this case, if the low-pressure gas pipe (22) is opened immediately, noise may be generated in the low-pressure valve (222) due to the pressure acting on the low-pressure valve (222). In order to prevent noise in the low-pressure valve (222) due to the pressure acting on the low-pressure valve (222), the pressure reducing valve (242) may be controlled to be opened. When the pressure reducing valve (242) is opened, the refrigerant can flow from one end of the pressure reducing tube (241) to the other end of the pressure reducing tube (241) through the pressure reducing tube (241). Accordingly, the pressure difference between the two sides of the low-pressure gas tube (22) with respect to the low-pressure valve (222) is reduced, thereby reducing noise generated from the low-pressure valve (222).

[0127] When the indoor unit (40A) is in cooling operation, the refrigerant may be in a high-temperature, high-pressure gaseous state as it passes through the compressor (11A, 11B). Thereafter, the refrigerant may flow to the outdoor heat exchanger (15) through the second port of the four-way valve (13). The refrigerant that has passed through the outdoor heat exchanger (15) may be in a high-temperature, high-pressure liquid state. The refrigerant that has passed through the outdoor heat exchanger (15) may flow to the liquid pipe (23) through the receiver tank (18). At this time, the liquid pipe valve (232) may be in an open state. The refrigerant that has passed through the liquid pipe (23) may flow to the connecting pipe (43A). At this time, the refrigerant may change to a low-temperature, low-pressure liquid state as it passes through the connecting pipe valve (44A). That is, the connecting pipe valve (44A) may function as an expansion valve. The refrigerant passing through the connection pipe (43A) can flow into the indoor unit (40A). The refrigerant flowing into the indoor unit (40A) can change into a low-temperature, low-pressure gaseous state through heat exchange with the indoor heat exchanger (42A). After the heat exchange, the indoor blower fan (41A) can blow air from the indoor heat exchanger (42A) side into the occupied space to cool the occupied space. The refrigerant passing through the indoor heat exchanger (42A) can flow into the low-pressure gas pipe (22) through the gas pipe connection pipe (261). The low-pressure valve (222) may be in an open state. At this time, since the high-pressure valve (212) is closed, the refrigerant can flow into the low-pressure gas pipe (22). Thereafter, the refrigerant can flow into the accumulator (19). The refrigerant flowing into the accumulator (19) can flow again into the compressor (11A, 11B) and be compressed to change into a high-temperature, high-pressure gaseous state. This can be called a cooling cycle or cooling mode.

[0128] The indoor unit (40A) may include a detector (45A). If refrigerant leaks from the refrigerant pipe (20) on the indoor unit (40A), the detector (45A) may be configured to detect the refrigerant leak. Based on the detection of refrigerant leakage by the detector (45A), the high-pressure valve (212), the low-pressure valve (222), the liquid pipe valve (232), the connection pipe valve (44A), and the pressure reducing valve (242) may be controlled. A specific control method related thereto will be described later.

[0129] The air conditioner (1) may include a control unit (110, see FIG. 13). The control unit (110) may be electrically connected to a detector (45A) and an on-off valve (200). The control unit (110) may be provided to control the opening and closing of a high-pressure valve (212), a low-pressure valve (222), a liquid pipe valve (232), a connection pipe valve (44A), and a pressure reducing valve (242), respectively. The control unit (110) may control the on-off valve (200) based on detection of a refrigerant leak in the detector (45A). Through this, the flow of refrigerant in the refrigerant pipe (20) may be controlled. The control unit (110) may control the opening and closing of a four-way valve (13).

[0130] The control unit (110) can control the operation of the air conditioner (1) based on an input signal of the cooling mode, heating mode, or stop mode. More specifically, the control unit (110) can control the low pressure valve (222) to be closed and the high pressure valve (212) and the liquid pipe valve (232) to be opened so that the air conditioner (1) is operated in the heating mode.

[0131] The control unit (110) can control to close the high pressure valve (212) and open the low pressure valve (222) and the liquid pipe valve (232) so that the air conditioner (1) operates in cooling mode. In addition, the control unit (110) can control to close the high pressure valve (212), the low pressure valve (222) and the liquid pipe valve (232) so that the air conditioner (1) stops. When the air conditioner (1) switches from heating mode to cooling mode, the opening and closing of the pressure reducing valve (242) can be controlled to reduce the pressure applied to the low pressure valve (222).

[0132] FIG. 4 is a diagram illustrating a state in which a control unit controls a liquid pipe valve to close a liquid pipe and block the flow of refrigerant toward the indoor unit when a detector detects a refrigerant leak while the indoor unit of an air conditioner is operating in cooling mode according to one embodiment. FIG. 5 is a diagram illustrating a state in which, when the refrigerant from the indoor unit side is recovered to the outdoor unit through the low-pressure gas pipe in FIG. 4 and the detector does not detect a refrigerant leak, the control unit controls a low-pressure valve to close the low-pressure gas pipe and a connection pipe valve to close the connection pipe. Hereinafter, a process of blocking the refrigerant pipe on the indoor unit side and recovering the refrigerant to the outdoor unit when a refrigerant leak occurs while the indoor unit is operating in cooling mode will be examined.

[0133] Referring to FIGS. 4 and 5, when the indoor unit (40A) is operating in cooling mode, the high-pressure gas pipe (21) may be closed and the low-pressure gas pipe (22) and liquid pipe (23) may be opened.

[0134] When the indoor unit (40A) is operating in cooling mode, liquid refrigerant can flow toward the indoor unit (40A) through the liquid pipe (23). The refrigerant flowing in the liquid pipe (23) can flow to the heat exchanger (42) of the indoor unit through the connecting pipe (43A) connected to the liquid pipe (23) and undergo heat exchange. At this time, the connecting pipe (43A) valve may be in an open state.

[0135] The refrigerant can change into a low-temperature, low-pressure gaseous state through heat exchange in the indoor heat exchanger (42A). The refrigerant that has passed through the indoor heat exchanger (42A) can flow into the low-pressure gas pipe (22) and be recovered to the outdoor unit (10).

[0136] When the indoor unit (40A) is operating in cooling mode, refrigerant flowing in the refrigerant pipe (20) may leak to the outside. There are various causes for refrigerant leakage. For example, refrigerant may leak due to damage to the refrigerant pipe (20).

[0137] When refrigerant leaks from the indoor unit (40A), the detector (45A) can detect the refrigerant leak. When the detector (45A) detects a refrigerant leak while the indoor unit (40A) is operating in cooling mode, the detector (45A) can generate a first detection signal (S1).

[0138] The control unit (110) is electrically connected to the detector (45A) and can receive a first detection signal (S1). The control unit (110) that receives the first detection signal (S1) can control the opening / closing valve (200).

[0139] When the indoor unit (40A) is operating in cooling mode and the detector (45A) detects a refrigerant leak in the refrigerant pipe (20) on the indoor unit (40A) side, the liquid pipe valve (232) can close the liquid pipe (23) to block the flow of refrigerant in the liquid pipe (23). When the indoor unit (40A) is operating in cooling mode, the refrigerant can flow into the indoor unit (40A) through the liquid pipe (23). As the liquid pipe (23) is blocked, the refrigerant may not flow into the refrigerant pipe (20) on the indoor unit (40A) side. Therefore, by closing the liquid pipe (23), the refrigerant flowing into the indoor unit (40A) can be blocked, thereby preventing further leakage of the refrigerant.

[0140] Since the low-pressure gas pipe (22) is open, the refrigerant remaining in the refrigerant pipe (20) on the indoor unit (40A) side can be recovered to the outdoor unit (10) side through the relatively low-pressure gas pipe (22) due to the pressure difference. Therefore, the phenomenon of additional refrigerant leakage from the refrigerant pipe (20) on the indoor unit (40A) side can be prevented. In addition, since the check valve (223) arranged in the low-pressure gas pipe (22) is installed to prevent the refrigerant flowing in the low-pressure gas pipe (22) from flowing from the outdoor unit (10) to the indoor unit (40A), the inflow of refrigerant into the indoor unit (40A) due to refrigerant backflow can be more effectively blocked.

[0141] In order to effectively recover the refrigerant remaining in the refrigerant pipe (20) on the indoor unit (40A) side to the outdoor unit (10), the connecting pipe (43A) may be provided to be open. That is, the connecting pipe valve (44A) may be provided to be open so that the refrigerant can flow in the connecting pipe (43A).

[0142] When the indoor unit (40A) is operating in cooling mode, the high-pressure gas pipe (21) is closed, so refrigerant may not flow into the indoor unit (40A). Accordingly, additional refrigerant leakage from the refrigerant pipe (20) on the indoor unit (40A) side can be prevented.

[0143] When the detector (45A) detects a refrigerant leak, the pressure reducing tube (241) can be closed. In other words, when the detector (45A) detects a refrigerant leak, the pressure reducing valve (242) can close the pressure reducing tube (241).

[0144] When the refrigerant remaining in the refrigerant pipe (20) on the indoor unit (40A) side is recovered to the outdoor unit (10) through the low-pressure gas pipe (22), the detector (45A) may no longer detect refrigerant leakage. This may be defined as completion of refrigerant recovery. At this time, the detector (45A) may generate a second detection signal (S2) indicating that refrigerant leakage is no longer detected.

[0145] The control unit (110) can control the opening / closing valve (200) by receiving the second detection signal (S2).

[0146] More specifically, when refrigerant recovery is completed, the connecting pipe (43A) can be closed. That is, the connecting pipe valve (44A) can be controlled to close the connecting pipe (43A). As the connecting pipe (43A) is closed, the refrigerant cannot flow in the connecting pipe (43A), thereby more effectively preventing the refrigerant from flowing into the indoor unit (40A).

[0147] When refrigerant recovery is complete, the low-pressure valve (222) can be operated to close the low-pressure gas pipe (22). Accordingly, the high-pressure gas pipe (21), low-pressure gas pipe (22), liquid pipe (23), pressure reducing pipe (241), and connecting pipe (43A) connected to the indoor unit (40A) can all be closed. This can more effectively prevent additional refrigerant leakage from the refrigerant pipe (20) on the indoor unit (40A) side.

[0148] When the indoor unit (40A) is not operating, the high-pressure gas pipe (21), the low-pressure gas pipe (22), and the liquid pipe (23) may all be blocked. When the detector (45A) detects a refrigerant leak while the indoor unit (40A) is not operating, the indoor unit (40A) may be controlled to operate in cooling mode. Thereafter, the on-off valve (200) may be controlled to follow a method of blocking the refrigerant pipe (20) on the indoor unit (40A) side and recovering the refrigerant to the outdoor unit (10) when a refrigerant leak occurs while the indoor unit (40A) is operating in cooling mode, as described above.

[0149] FIG. 6 is a diagram illustrating a state in which, when a detector detects a refrigerant leak while the indoor unit of an air conditioner is operating in heating mode according to one embodiment, the control unit controls a high-pressure valve to close a high-pressure gas pipe to block the flow of refrigerant toward the indoor unit, controls a low-pressure valve to open a low-pressure gas pipe to return the refrigerant to the outdoor unit, and controls a liquid pipe valve to close the liquid pipe. FIG. 7 is a diagram illustrating a state in which, when the refrigerant from the indoor unit is returned to the outdoor unit through the low-pressure gas pipe in FIG. 6 and the detector does not detect a refrigerant leak, the control unit controls a low-pressure valve to close the low-pressure gas pipe and controls a connection pipe valve to close the connection pipe. Hereinafter, the process in which the refrigerant pipe on the indoor unit side is blocked and the refrigerant is returned to the outdoor unit when a refrigerant leak occurs while the indoor unit is operating in heating mode will be examined.

[0150] Referring to FIGS. 6 and 7, when the indoor unit (40A) is operating in heating mode, the low-pressure gas pipe (22) may be closed and the high-pressure gas pipe (21) and the liquid pipe (23) may be opened.

[0151] When the indoor unit (40A) is operating in heating mode, a gaseous refrigerant may flow toward the indoor unit (40A) through the high-pressure gas pipe (21). The refrigerant flowing in the high-pressure gas pipe (21) may change into a liquid state through the heat exchanger (42) of the indoor unit and then flow into the connecting pipe (43A). At this time, the valve of the connecting pipe (43A) may be open. Thereafter, the refrigerant may flow into the liquid pipe (23) and be recovered to the outdoor unit (10).

[0152] When the indoor unit (40A) is operating in heating mode, the refrigerant flowing in the refrigerant pipe (20) may leak to the outside. The causes of the refrigerant leakage may be various as described above.

[0153] When refrigerant leaks from the indoor unit (40A), the detector (45A) can detect the refrigerant leak. When the detector (45A) detects a refrigerant leak while the indoor unit (40A) is operating in heating mode, the detector (45A) can generate a third detection signal (S3).

[0154] The control unit (110) is electrically connected to the detector (45A) and can receive a third detection signal (S3). The control unit (110) that receives the third detection signal (S3) can control the opening / closing valve (200).

[0155] When the indoor unit (40A) is operating in heating mode and the detector (45A) detects a refrigerant leak in the refrigerant pipe (20) on the indoor unit (40A) side, the high-pressure valve (212) can close the high-pressure gas pipe (21) to block the flow of refrigerant in the high-pressure gas pipe (21). When the indoor unit (40A) is operating in heating mode, the refrigerant can flow into the indoor unit (40A) through the high-pressure gas pipe (21). As the high-pressure gas pipe (21) is blocked, the refrigerant may not flow into the refrigerant pipe (20) on the indoor unit (40A) side. Therefore, by closing the high-pressure gas pipe (21), the refrigerant flowing into the indoor unit (40A) can be blocked, thereby preventing further leakage of the refrigerant.

[0156] When the indoor unit (40A) is operating in heating mode and the detector (45A) detects a refrigerant leak in the refrigerant pipe (20) on the indoor unit (40A) side, the liquid pipe valve (232) can close the liquid pipe (23) to block the flow of refrigerant in the liquid pipe (23).

[0157] When the indoor unit (40A) is operating in heating mode and the detector (45A) detects a refrigerant leak in the refrigerant pipe (20) on the indoor unit (40A) side, the low-pressure valve (222) can open the low-pressure gas pipe (22). The refrigerant remaining in the refrigerant pipe (20) on the indoor unit (40A) side can flow to the relatively low-pressure gas pipe (22) due to the pressure difference and can be recovered to the outdoor unit (10) side. Therefore, the phenomenon of additional refrigerant leaking from the refrigerant pipe (20) on the indoor unit (40A) side can be prevented. In addition, the check valve (223) placed in the low-pressure gas pipe (22) is installed to prevent the refrigerant flowing in the low-pressure gas pipe (22) from flowing from the outdoor unit (10) to the indoor unit (40A), so that the refrigerant inflow into the indoor unit (40A) due to the refrigerant backflow can be more effectively blocked.

[0158] When the detector (45A) detects a refrigerant leak, the pressure reducing tube (241) can be closed. In other words, when the detector (45A) detects a refrigerant leak, the pressure reducing valve (242) can close the pressure reducing tube (241).

[0159] When the refrigerant remaining in the refrigerant pipe (20) on the indoor unit (40A) side is recovered to the outdoor unit (10) through the low-pressure gas pipe (22), the detector (45A) may not detect a refrigerant leak. This may be defined as completion of refrigerant recovery. At this time, the detector (45A) may generate a fourth detection signal (S4) indicating that no further refrigerant leak is detected.

[0160] The control unit (110) can control the opening / closing valve (200) by receiving the fourth detection signal (S4).

[0161] More specifically, when refrigerant recovery is completed, the connecting pipe (43A) can be closed. That is, the connecting pipe valve (44A) can be controlled to close the connecting pipe (43A). As the connecting pipe (43A) is closed, the refrigerant cannot flow in the connecting pipe (43A), thereby more effectively preventing the refrigerant from flowing into the indoor unit (40A).

[0162] When refrigerant recovery is complete, the low-pressure valve (222) can be operated to close the low-pressure gas pipe (22). Accordingly, the high-pressure gas pipe (21), low-pressure gas pipe (22), liquid pipe (23), pressure reducing pipe (241), and connecting pipe (43A) connected to the indoor unit (40A) can all be closed. This can more effectively prevent additional refrigerant leakage from the refrigerant pipe (20) on the indoor unit (40A) side.

[0163] FIG. 8 is a schematic diagram illustrating the structure of a multi-air conditioner according to one embodiment. FIG. 9 is an enlarged diagram illustrating a part of a cooling / heating switching device and an indoor unit of a multi-air conditioner according to one embodiment, and is a diagram illustrating a state in which a control unit controls a first liquid pipe valve to block the flow of refrigerant toward the first indoor unit by closing the first liquid pipe connected to the first indoor unit when a first detector detects a refrigerant leak while the first indoor unit is operating in cooling mode. FIG. 10 is a diagram illustrating a state in which, when the refrigerant from the first indoor unit side is recovered to the outdoor unit through the first low-pressure gas pipe in FIG. 9 and the first detector does not detect a refrigerant leak, a control unit controls the first low-pressure valve to close the first low-pressure gas pipe and controls the first connection pipe valve to close the first connection pipe. In the following, descriptions of content overlapping with the above will be omitted.

[0164] Referring to FIGS. 8 and 10, the multi-air conditioner (3) can be arranged to cool or heat each room that requires occupancy.

[0165] Below, the schematic configuration of the multi-air conditioner (3) is described.

[0166] The multi-air conditioner (3) may include an outdoor unit (10). The outdoor unit (10) may be installed on the outdoor side.

[0167] The multi-air conditioner (3) may include an indoor unit (40). The indoor unit (40) may be installed on the indoor side where occupancy is required. The indoor unit (40) may be connected to the outdoor unit (10). The indoor unit (40) may include a plurality of indoor units (40A, 40B, 40C, 40D, 40E, 40F). Although the number of indoor units is illustrated as six, the number of indoor units is not limited thereto and may be provided in various ways.

[0168] Each indoor unit (40) may include an indoor heat exchanger (42). The indoor heat exchanger (42) may include a plurality of indoor heat exchangers (42A, 42B, 42C, 42D, 42E, 42F). The indoor heat exchanger (42) may be provided so that the refrigerant passing through the indoor heat exchanger (42) undergoes heat exchange.

[0169] The indoor unit (40) may include an indoor blower fan (41). The indoor blower fan (41A) may include a plurality of indoor blower fans (41A, 41B, 41C, 41D, 41E, 41F). The indoor blower fan (41) may blow air from the indoor heat exchanger (42) side to a room requiring refrigeration after heat exchange of the refrigerant occurs in the indoor heat exchanger (42).

[0170] The multi-air conditioner (3) may include a refrigerant pipe (20). The refrigerant pipe (20) may be provided to connect an outdoor unit (10) and a plurality of indoor units (40A, 40B, 40C, 40D, 40E, 40F) to allow refrigerant to flow. The multi-air conditioner (3) may include an on-off valve (200). The on-off valve (200) may be provided to open and close the refrigerant pipe (20) to control the flow of refrigerant in the refrigerant pipe (20).

[0171] The refrigerant pipe (20) may include a high-pressure gas pipe (21) provided to supply refrigerant to each of a plurality of indoor units (40A, 40B, 40C, 40D, 40E, 40F). The high-pressure gas pipe (21) may branch to supply high-temperature, high-pressure refrigerant from the outdoor unit (10) to each of the plurality of indoor units (40A, 40B, 40C, 40D, 40E, 40F), thereby connecting the outdoor unit (10) and the plurality of indoor units (40A, 40B, 40C, 40D, 40E, 40F).

[0172] The refrigerant pipe (20) may include a low-pressure gas pipe (22) provided to recover the refrigerant to the outdoor unit (10). The low-pressure gas pipe (22) may be provided to recover the refrigerant in a low-temperature, low-pressure state from each indoor unit (40A) to the outdoor unit (10). The low-pressure gas pipe (22) may branch to connect a plurality of indoor units (40A, 40B, 40C, 40D, 40E, 40F) and the outdoor unit (10).

[0173] The refrigerant pipe (20) may include a liquid pipe (23). The liquid pipe (23) may be provided to branch and connect a plurality of indoor units (40A, 40B, 40C, 40D, 40E, 40F) and the outdoor unit (10). A liquid refrigerant may flow in the liquid pipe (23). Through the liquid pipe (23), the refrigerant may be provided to be supplied from the outdoor unit (10) to the plurality of indoor units (40A, 40B, 40C, 40D, 40E, 40F), or to be recovered from the plurality of indoor units (40A, 40B, 40C, 40D, 40E, 40F) to the outdoor unit (10).

[0174] The refrigerant pipe (20) may include a pressure reducing pipe (241). The pressure reducing pipe (241) may be arranged to be connected to a low-pressure gas pipe (22). More specifically, one end of the pressure reducing pipe (241) may be connected upstream of the low-pressure valve (222) with respect to the flow direction of the refrigerant in the low-pressure gas pipe (22). And, the other end of the pressure reducing pipe (241) may be connected downstream of the low-pressure valve (222) with respect to the flow direction of the refrigerant in the low-pressure gas pipe (22).

[0175] The refrigerant pipe (20) may include a gas pipe connecting pipe (261). The gas pipe connecting pipe (261) may connect the high-pressure gas pipe (21) to the indoor unit (40). The gas pipe connecting pipe (261) may connect the low-pressure gas pipe (22) to the indoor unit (40). One end of the gas pipe connecting pipe (261) may be joined to the high-pressure gas pipe (21). One end of the gas pipe connecting pipe (261) may be joined to the low-pressure gas pipe (22). The other end of the gas pipe connecting pipe (261) may be connected to the indoor unit (40).

[0176] The multi-air conditioner (3) may include a heating and cooling switching device (30). The heating and cooling switching device (30) may include a part of a refrigerant pipe (20). The heating and cooling switching device (30) may perform a full-room heating operation in which all indoor units are operated for heating, a full-room cooling operation in which all indoor units are operated for cooling, a heating-only operation in which a small number of indoor units are operated for cooling and the remaining large number of indoor units are operated for heating, and a cooling-only operation in which a small number of indoor units are operated for heating and the remaining large number of indoor units are operated for cooling.

[0177] That is, the heating and cooling switching device (30) may include a control unit (110). The control unit (110) may control the opening and closing of the refrigerant pipe (20) connected to each indoor unit (40A, 40B, 40C, 40D, 40E, 40F), thereby controlling the multi-air conditioner (3) to perform full-room heating operation, full-room cooling operation, heating main operation, and cooling main operation. That is, each of the multiple indoor units (40A, 40B, 40C, 40D, 40E, 40F) may perform heating operation or cooling operation.

[0178] Below, the operation of the multi-air conditioner (3) is explained by explaining that the first indoor unit (40A) operates in cooling mode and the second indoor unit (40B) operates in heating mode.

[0179] The on-off valve (200) may include a high-pressure valve (212). The high-pressure valve (212) may be provided in the high-pressure gas pipe (21). When the high-pressure valve (212) is closed, the high-pressure gas pipe (21) is blocked, and refrigerant may not flow in the high-pressure gas pipe (21).

[0180] The high-pressure gas pipe (21) may be branched and connected to a plurality of indoor units (40A, 40B, 40C, 40D, 40E, 40F), respectively. The high-pressure gas pipe (21) may include a first high-pressure gas pipe (211A) branched and connected to the first indoor unit (40A).

[0181] A first high-pressure gas pipe (211A) may be provided with a first high-pressure valve (212A). The refrigerant pipe (20) may include a first gas pipe connection pipe (261A) connected to the first indoor unit (40A). The first high-pressure gas pipe (211A) may be combined with the first gas pipe connection pipe (261A).

[0182] The second indoor unit (40B) may be connected to a second high-pressure gas pipe (211B). A second high-pressure valve (212B) may be provided in the second high-pressure gas pipe (211B). The refrigerant pipe (20) may include a second gas pipe connection pipe (261B) connected to the second indoor unit (40B). The second high-pressure gas pipe (211B) may be combined with the second gas pipe connection pipe (261B).

[0183] The on-off valve (200) may include a low-pressure valve (222). The low-pressure valve (222) may be provided in the low-pressure gas pipe (22). When the low-pressure valve (222) is closed, the low-pressure gas pipe (22) is blocked, and refrigerant may not flow in the low-pressure gas pipe (22).

[0184] The low-pressure gas pipe (22) can be branched and connected to multiple indoor units (40A, 40B, 40C, 40D, 40E, 40F).

[0185] The low-pressure gas pipe (22) may include a first low-pressure gas pipe (221A) that branches and is connected to the first indoor unit (40A). A first low-pressure valve (222A) may be provided in the first low-pressure gas pipe (221A). The refrigerant pipe (20) may include a first gas pipe connection pipe (261A) that is connected to the first indoor unit (40A). The first low-pressure gas pipe (221A) may be combined with the first gas pipe connection pipe (261A).

[0186] The second indoor unit (40B) may be connected to a second low-pressure gas pipe (221B). A second low-pressure valve (222B) may be provided in the second low-pressure gas pipe (221B). The refrigerant pipe (20) may include a second gas pipe connection pipe (261B) connected to the second indoor unit (40B). The second low-pressure gas pipe (221B) may be combined with the second gas pipe connection pipe (261B).

[0187] The on-off valve (200) may include a liquid pipe (23) valve. The liquid pipe (23) valve may be provided in the liquid pipe (23). When the liquid pipe (23) valve is closed, the liquid pipe (23) is blocked, so that refrigerant may not flow in the liquid pipe (23).

[0188] The liquid pipe (23) can be branched and connected to multiple indoor units (40A, 40B, 40C, 40D, 40E, 40F).

[0189] The liquid pipe (23) may include a first liquid pipe (231A) that is branched and connected to the first indoor unit (40A). A first liquid pipe valve (232A) may be provided in the first liquid pipe (231A).

[0190] The second indoor unit (40B) can be connected to the second liquid pipe (231B). A second liquid pipe valve (232B) can be provided in the second liquid pipe (231B).

[0191] The refrigerant pipe (20) may include a connecting pipe (43). The connecting pipe (43) may connect the liquid pipe (23) and the indoor unit (40). One end of the connecting pipe (43) may be joined to the liquid pipe (23). The other end of the connecting pipe (43) may be connected to the indoor unit (40).

[0192] The refrigerant pipe (20) may include a connecting pipe valve (44). The connecting pipe valve (44) may be provided in the connecting pipe (43). When the connecting pipe valve (44) is closed, the connecting pipe (43) is blocked, so that the refrigerant may not flow in the connecting pipe (43).

[0193] The first indoor unit (40A) can be connected to the first connecting pipe (43A). The first connecting pipe (43A) can be provided with a first connecting pipe valve (44A).

[0194] The second indoor unit (40B) can be connected to a second connecting pipe (43B). A second connecting pipe valve (44B) can be provided in the second connecting pipe (43B).

[0195] The refrigerant pipe (20) may include a pressure reducing valve (242). The pressure reducing valve (242) may be provided in the pressure reducing pipe (241).

[0196] A first pressure reducing valve (242A) may be provided in the first pressure reducing tube (241A). A second pressure reducing valve (242B) may be provided in the second pressure reducing tube (241B).

[0197] The heating and cooling switching device (30) may include a control unit (110). The control unit (110) may be electrically connected to the detectors (45A, 45B, 45C, 45D, 45E, 45F) and the on-off valves (200) included in each of the plurality of indoor units (40A, 40B, 40C, 40D, 40E, 40F). The control unit (110) may control the on-off valves (200) to control the opening and closing of the refrigerant pipe (20). The control unit (110) may control the opening and closing of the high-pressure valve (212), the low-pressure valve (222), the liquid pipe (23) valve, and the pressure reducing valve (242) to control the flow of refrigerant in the refrigerant pipe (20).

[0198] The control unit (110) may be configured to control the opening and closing of the refrigerant pipe (20) connected to the first indoor unit (40A) and the refrigerant pipe (20) connected to the second indoor unit (40B), so that the first indoor unit (40A) and the second indoor unit (40B) can operate independently. More specifically, the control unit (110) may close the first high-pressure valve (212A) and open the first low-pressure valve (222A) and the first liquid pipe (231A) valves so that the first indoor unit (40A) performs a cooling operation. In addition, the control unit (110) may control the closing of the second low-pressure valve (222B) and the opening of the second high-pressure valve (212B) and the second liquid pipe (231B) valves so that the second indoor unit (40B) performs a heating operation.

[0199] As described above, the third indoor unit (40C) and the fourth indoor unit (40D) can also be arranged to operate independently by controlling the opening and closing of the refrigerant pipe (20) connected to the third indoor unit (40C) or the fourth indoor unit (40D) by the control unit (110). It goes without saying that the fifth indoor unit (40E) and the sixth indoor unit (40F) illustrated in Fig. 7 can also be operated independently by being controlled by the control unit (110) by including the above-described structure.

[0200] Below, when the first indoor unit (40A) operates in cooling mode and refrigerant leaks, the process of blocking the inflow of refrigerant into the first indoor unit (40A) and recovering the refrigerant on the first indoor unit (40A) side is examined.

[0201] When the first indoor unit (40A) is operating in cooling mode, the first high-pressure gas pipe (211A) may be closed and the first low-pressure gas pipe (221A) and the first liquid pipe (231A) may be opened.

[0202] When a refrigerant leak occurs in the refrigerant pipe (20) on the first indoor unit (40A) side while the first indoor unit (40A) is operating in cooling mode, the detector (45A) of the first indoor unit (40A) can detect the refrigerant leak and generate a first detection signal (S1).

[0203] The control unit (110) can receive the first detection signal (S1) and control the on-off valve (200). When a refrigerant leak occurs in the refrigerant pipe (20) on the first indoor unit (40A) side while the first indoor unit (40A) is operating in cooling mode, the first liquid pipe valve (232A) can be closed to block the refrigerant from flowing into the first indoor unit (40A) through the first liquid pipe (231A). This can prevent additional refrigerant leakage from the first indoor unit (40A). In addition, the first pressure reducing valve (242A) can be closed to block the first pressure reducing pipe (241A), thereby preventing additional refrigerant from flowing in.

[0204] The refrigerant remaining on the first indoor unit (40A) side can be recovered to the outdoor unit (10) through the first low-pressure gas pipe (221A). In order to effectively recover the refrigerant remaining on the first indoor unit (40A) side to the outdoor unit (10), the first connection pipe valve (44A) can be arranged to be opened. The control unit (110) can receive the first detection signal (S1) and open the connection pipe valve (44A). Through this, the refrigerant remaining on the first indoor unit (40A) side can be recovered to the outdoor unit (10) more effectively.

[0205] When the refrigerant remaining in the refrigerant pipe (20) of the first indoor unit (40A) is recovered to the outdoor unit (10) through the first low-pressure gas pipe (221A), the detector (45A) of the first indoor unit (40A) may no longer detect refrigerant leakage. This may be defined as completion of refrigerant recovery. At this time, the detector (45A) of the first indoor unit (40A) may generate a second detection signal (S2) indicating that refrigerant leakage is no longer detected.

[0206] The control unit (110) can receive the second detection signal (S2) and control the on-off valve (200). More specifically, when the refrigerant recovery is complete, the first connection valve can be closed to block the first connection pipe (43A). When the refrigerant recovery is complete, the first low-pressure valve (222A) can be closed to block the first low-pressure gas pipe (221A). This effectively prevents the refrigerant from flowing into the first indoor unit (40A).

[0207] When the first indoor unit (40A) is not operating, the first high-pressure gas pipe (211A), the first low-pressure gas pipe (221A), and the first liquid pipe (231A) may all be blocked. When the detector (45A) of the first indoor unit (40A) detects a refrigerant leak while the first indoor unit (40A) is not operating, the first indoor unit (40A) may be controlled to operate in cooling mode. Thereafter, the on-off valve (200) may be controlled to follow a method of blocking the refrigerant pipe (20) on the first indoor unit (40A) side and recovering the refrigerant to the outdoor unit (10) when the first indoor unit (40A) is operating in cooling mode, as described above.

[0208] FIG. 11 is an enlarged view of a part of a heating / cooling switching device and an indoor unit of a multi-air conditioner according to one embodiment, and illustrates a state in which, when a first detector detects a refrigerant leak while the first indoor unit is operating in heating mode, the control unit controls the first high-pressure valve to close the first high-pressure gas pipe to block the refrigerant flow toward the first indoor unit, controls the first low-pressure valve to open the first low-pressure gas pipe to return the refrigerant to the outdoor unit, and controls the first liquid pipe valve to close the first liquid pipe. FIG. 12 is a view illustrating a state in which, when the refrigerant from the first indoor unit side of FIG. 11 is returned to the outdoor unit through the first low-pressure gas pipe and the first detector does not detect a refrigerant leak, the control unit controls the first low-pressure valve to close the first low-pressure gas pipe and controls the first connection pipe valve to close the first connection pipe. Descriptions of content overlapping with the above will be omitted below.

[0209] Referring to FIGS. 11 and 12, when the first indoor unit (40A) is operating in heating mode, the first low-pressure gas pipe (221A) may be closed and the first high-pressure gas pipe (211A) and the first liquid pipe (231A) may be opened.

[0210] When the first indoor unit (40A) is operating in heating mode, if a refrigerant leak occurs in the refrigerant pipe (20) on the first indoor unit (40A) side, the detector (45A) of the first indoor unit (40A) can detect the refrigerant leak and generate a third detection signal (S3).

[0211] The control unit (110) can receive the third detection signal (S3) and control the on-off valve (200). When a refrigerant leak occurs in the refrigerant pipe (20) on the first indoor unit (40A) side while the first indoor unit (40A) is operating in heating mode, the first high-pressure valve (212A) can be closed to block the refrigerant from flowing into the first indoor unit (40A) through the first high-pressure gas pipe (211A). This can prevent additional refrigerant leakage from the first indoor unit (40A). In addition, the first pressure-reducing valve (242A) can be closed to block the first pressure-reducing pipe (241A), thereby preventing additional refrigerant from flowing in.

[0212] The control unit (110) may receive the third detection signal (S3) to close the first liquid pipe valve (232A) to block the first liquid pipe (231A). The control unit (110) may receive the third detection signal (S3) to open the first low-pressure valve (222A) to allow the refrigerant to flow in the first low-pressure gas pipe (221A). The refrigerant remaining on the first indoor unit (40A) side may be recovered to the outdoor unit (10) through the first low-pressure gas pipe (221A). The control unit (110) may receive the third detection signal (S3) to open the connection pipe valve (44A). Through this, the refrigerant remaining on the first indoor unit (40A) side may be recovered to the outdoor unit (10) more effectively.

[0213] When the refrigerant remaining in the refrigerant pipe (20) of the first indoor unit (40A) is recovered to the outdoor unit (10) through the first low-pressure gas pipe (221A), the detector (45A) of the first indoor unit (40A) may no longer detect refrigerant leakage. This may be defined as completion of refrigerant recovery. At this time, the detector (45A) of the first indoor unit (40A) may generate a fourth detection signal (S4) indicating that refrigerant leakage is no longer detected.

[0214] The control unit (110) can receive the fourth detection signal (S4) and control the on-off valve (200). More specifically, when the refrigerant recovery is complete, the first connection valve can be closed to block the first connection pipe (43A). When the refrigerant recovery is complete, the first low-pressure valve (222A) can be closed to block the first low-pressure gas pipe (221A). This effectively prevents the refrigerant from flowing into the first indoor unit (40A).

[0215] Fig. 13 is a control block diagram for explaining an air conditioner according to one embodiment.

[0216] Referring to Fig. 13, the air conditioner (1) may include a control unit (110). As previously discussed, the control unit (110) may be electrically connected to a detector (45) and an on-off valve (200). The control unit (110) may receive a detection signal generated from the detector (45). The control unit (110) may control the opening and closing of a high-pressure valve (212), a low-pressure valve (222), a liquid pipe valve (232), a connection pipe valve (44A), and a pressure reducing valve (242) included in the on-off valve (200).

[0217] The air conditioner (1) may include a memory (120). The memory (120) may be electrically connected to the control unit (110). The memory (120) may store data regarding an algorithm for the control unit (110) to control the opening / closing valve (200) or a program reproducing the algorithm.

[0218] The memory (120) and the control unit (110) may be implemented as separate chips. Alternatively, the memory (120) and the control unit (110) may be implemented as a single chip.

[0219] Figure 14 is a flowchart illustrating a method for a control unit to control an on-off valve according to a refrigerant leak when an air conditioner is in cooling mode according to one embodiment. Below, the process of blocking the inflow of refrigerant to the indoor unit and recovering refrigerant to the outdoor unit when the indoor unit is in cooling mode is examined from the perspective of the control unit controlling the on-off valve. Descriptions of any content that overlaps with the above will be omitted.

[0220] Referring to Fig. 14, when a user inputs that the indoor unit (40A) be operated in cooling mode, the control unit (110) can control the on-off valve (200) to close the high-pressure gas pipe (21) and thereby close the high-pressure valve (212). In addition, the control unit (110) can control the on-off valve (200) to open the low-pressure gas pipe (22) and thereby open the low-pressure valve (222). In addition, the control unit (110) can control the on-off valve (200) to open the liquid pipe (23) and thereby open the liquid pipe valve (232) (1010).

[0221] When a refrigerant leak is detected by the detector (45A) when the indoor unit (40A) is operating in cooling mode (1020), the control unit (110) can control the liquid pipe valve (232) to close the liquid pipe (23) to prevent the inflow of refrigerant to the indoor unit (40A) (1030). The refrigerant remaining in the refrigerant pipe (20) on the indoor unit (40A) side can be recovered to the outdoor unit (10) through the low-pressure gas pipe (22).

[0222] Thereafter, when the refrigerant recovery to the outdoor unit (10) is completed and no refrigerant leakage is detected by the detector (45A) (1040), the control unit (110) can control the low-pressure valve (222) to close the low-pressure gas pipe (22) (1050). Through this, all refrigerant pipes (20) on the indoor unit (40A) side can be closed.

[0223] Figure 15 is a flowchart illustrating a method in which a control unit controls an on-off valve according to a refrigerant leak when an air conditioner is in heating mode, according to one embodiment. Below, the process of blocking the inflow of refrigerant to the indoor unit and recovering refrigerant to the outdoor unit when the indoor unit is in heating mode is examined from the perspective of the control unit controlling the on-off valve. Descriptions of any content that overlaps with the above will be omitted.

[0224] Referring to Fig. 15, when a user inputs that the indoor unit (40A) be operated in heating mode, the control unit (110) can control the on-off valve (200) to close the low-pressure gas pipe (22) and thereby close the low-pressure valve (222). In addition, the control unit (110) can control the on-off valve (200) to open the high-pressure gas pipe (21) and thereby open the high-pressure valve (212). In addition, the control unit (110) can control the on-off valve (200) to open the liquid pipe (23) and thereby open the liquid pipe valve (232) (2010).

[0225] When a refrigerant leak is detected by the detector (45A) when the indoor unit (40A) is operating in heating mode (2020), the control unit (110) can control the high-pressure valve (212) to close the high-pressure gas pipe (21) to prevent the inflow of refrigerant toward the indoor unit (40A) (2030). In addition, the control unit (110) can control the liquid pipe valve (232) to close the liquid pipe (23) (2040). In addition, the control unit (110) can control the low-pressure valve (222) to open the low-pressure gas pipe (22) (2050). When the low-pressure gas pipe (22) is opened, the refrigerant in the refrigerant pipe (20) on the indoor unit (40A) side can be recovered to the outdoor unit (10) through the low-pressure gas pipe (22) due to the pressure difference.

[0226] Thereafter, when the refrigerant recovery to the outdoor unit (10) is completed and no refrigerant leakage is detected by the detector (45A) (2060), the control unit (110) can control the low-pressure valve (222) to close the low-pressure gas pipe (22) (2070). Through this, all refrigerant pipes (20) on the indoor unit (40A) side can be closed.

[0227] Figure 16 is a flowchart illustrating a method by which a control unit controls an on-off valve according to a refrigerant leak when an air conditioner is not operating according to one embodiment. Below, the process of recovering refrigerant to the outdoor unit when the indoor unit is in heating mode is examined from the perspective of the control unit controlling the on-off valve. Any descriptions that overlap with the above will be omitted.

[0228] Referring to Fig. 16, when the indoor unit (40A) is not operating, the control unit (110) can control the opening / closing valve (200) so that the high-pressure gas pipe (21), the low-pressure gas pipe (22), and the liquid pipe (23) are closed. That is, the control unit (110) can control the high-pressure valve (212), the low-pressure valve (222), and the liquid pipe valve (232) to be closed (3010).

[0229] When a refrigerant leak is detected by the detector (45A) when the indoor unit (40A) is not operating (3020), the control unit (110) can control the low-pressure valve (222) to open the low-pressure gas pipe (22) (3030). The refrigerant remaining in the refrigerant pipe (20) on the indoor unit (40A) side can be recovered to the outdoor unit (10) through the low-pressure gas pipe (22).

[0230] Thereafter, when the refrigerant recovery to the outdoor unit (10) is completed and no refrigerant leakage is detected by the detector (45A) (3040), the control unit (110) can control the low-pressure valve (222) to close the low-pressure gas pipe (22) (3050). Through this, all refrigerant pipes (20) on the indoor unit (40A) side can be closed.

[0231] Fig. 17 is a flowchart illustrating a method for controlling a connecting pipe valve when a refrigerant leak occurs in an air conditioner according to one embodiment. Fig. 18 is a flowchart illustrating a method for controlling a pressure reducing valve when a refrigerant leak occurs in an air conditioner according to one embodiment. The process for controlling the connecting pipe valve and the pressure reducing valve when a refrigerant leak occurs can be applied equally whether the indoor unit is in cooling mode, heating mode, or stop mode.

[0232] Referring to FIGS. 17 and 18, when a refrigerant leak is detected by the detector (45A), the control unit (110) can control the valve of the connection pipe (43A) to open the connection pipe (43A) (4010). Through this, the refrigerant remaining in the refrigerant pipe (20) on the indoor unit (40A) side can be more effectively recovered to the outdoor unit (10) through the low-pressure gas pipe (22).

[0233] After the refrigerant recovery to the outdoor unit (10) is completed and no refrigerant leakage is detected by the detector (45A) (4020), the control unit (110) can control the connection pipe valve (44A) to close the connection pipe (43A) (4030) and control the pressure reducing valve (242) to close the pressure reducing pipe (241) (5010). This can more effectively prevent refrigerant from flowing into the indoor unit (40A).

[0234] An air conditioner (1) according to one embodiment includes an outdoor unit (10), a detector (45A) for detecting a refrigerant leak, and an indoor unit (40A) connected to the outdoor unit (10). The air conditioner (1) includes a high-pressure gas pipe (21) provided to supply refrigerant from the outdoor unit (10) to the indoor unit (40A). The air conditioner (1) includes a low-pressure gas pipe (22) provided to recover refrigerant from the indoor unit (40A) to the outdoor unit (10). The air conditioner (1) includes a liquid pipe (23) provided to supply refrigerant from the outdoor unit (10) to the indoor unit (40A) or to recover refrigerant from the indoor unit (40A) to the outdoor unit (10). The air conditioner (1) includes an on-off valve (200) configured to open and close the high-pressure gas pipe (21), the low-pressure gas pipe (22), and the liquid pipe (23). The air conditioner (1) includes a control unit (110) electrically connected to the detector (45A) and the on-off valve (200). The control unit (110) controls the on-off valve (200) so that the refrigerant is recovered from the indoor unit (40A) to the outdoor unit (10) through the low-pressure gas pipe (22) based on the detection of a refrigerant leak by the detector (45A).

[0235] The above-mentioned opening / closing valve (200) may include a high-pressure valve (212) provided to open / close the high-pressure gas pipe (21). The above-mentioned opening / closing valve (200) may include a low-pressure valve (222) provided to open / close the low-pressure gas pipe (22). The above-mentioned opening / closing valve (200) may include a liquid pipe valve (232) provided to open / close the liquid pipe (23). The above-mentioned control unit (110) may control the high-pressure valve (212), the low-pressure valve (222), and the liquid pipe valve (232), respectively.

[0236] When the indoor unit (40A) is operating in cooling mode, the high-pressure gas pipe (21) may be closed and the low-pressure gas pipe (22) and the liquid pipe (23) may be provided to be open (1010). The control unit (110) may control the liquid pipe valve (232) (1030) to close the liquid pipe (23) and block the flow of refrigerant to the indoor unit (40A) based on the detection (1020) of a refrigerant leak by the detector (45A) while the indoor unit (40A) is operating in cooling mode.

[0237] The refrigerant on the indoor unit (40A) side may be arranged to be recovered to the outdoor unit (10) through the low-pressure gas pipe (22). The control unit (110) may control (1050) the low-pressure valve (222) to close the low-pressure gas pipe (22) based on the fact that the refrigerant recovery is complete and no refrigerant leakage is detected by the detector (45A) (1040).

[0238] When the indoor unit (40A) is operating in heating mode, the low-pressure gas pipe (22) may be closed and the high-pressure gas pipe (21) and the liquid pipe (23) may be provided to be open (2010). The control unit (110) may control the high-pressure valve (212) (2030) to close the high-pressure gas pipe (21) and block the flow of refrigerant to the indoor unit (40A) based on the detection (2020) of a refrigerant leak by the detector (45A) while the indoor unit (40A) is operating in heating mode.

[0239] The above control unit (110) can control (2040) the liquid pipe valve (232) to close the liquid pipe (23) based on the detection (2020) of a refrigerant leak by the detector (45A) while the indoor unit (40A) is operating in heating mode.

[0240] The above control unit (110) can control the low-pressure valve (222) (2050) to open the low-pressure gas pipe (22) and allow the refrigerant on the indoor unit (40A) side to be recovered to the outdoor unit (10) based on the detection (2020) of a refrigerant leak by the detector (45A) while the indoor unit (40A) is operating in heating mode.

[0241] The above control unit (110) can control (2070) the low-pressure valve (222) to close the low-pressure gas pipe (22) based on the fact that refrigerant recovery is complete and no refrigerant leakage is detected by the detector (45A) (2060).

[0242] When the indoor unit (40A) is not in operation, the high-pressure gas pipe (21), the low-pressure gas pipe (22), and the liquid pipe (23) may be arranged to be closed (3010). The control unit (110) may control the low-pressure valve (222) (3030) to open the low-pressure gas pipe (22) based on the detection (3020) of a refrigerant leak by the detector (45A) when the indoor unit (40A) is not in operation so that the refrigerant on the indoor unit (40A) side is recovered to the outdoor unit (10).

[0243] The above air conditioner (1) may further include a check valve (223) positioned upstream of the low-pressure valve (222) with respect to the flow direction of the refrigerant in the low-pressure gas pipe (22). The check valve (223) may be provided to prevent the refrigerant flowing in the low-pressure gas pipe (22) from flowing from the outdoor unit (10) to the indoor unit (40A).

[0244] The air conditioner (1) may further include a connecting pipe (43A) that connects the liquid pipe (23) and the heat exchanger (42) of the indoor unit, including one end that is connected to the liquid pipe (23) and the other end that is connected to the heat exchanger (42) of the indoor unit. The opening / closing valve (200) may further include a connecting pipe valve (44A) that is provided to open and close the connecting pipe (43A) and is controlled by the control unit (110). The control unit (110) may control (4010) the connecting pipe valve (44A) so that the connecting pipe (43A) is opened based on the detection of a refrigerant leak by the detector (45A).

[0245] The refrigerant on the indoor unit (40A) side may be arranged to be recovered to the outdoor unit (10) through the low-pressure gas pipe (22). The control unit (110) may control the low-pressure valve (222) to close the low-pressure gas pipe (22) and control the connection pipe valve (44A) to close the connection pipe (43A) (4030) based on the fact that the refrigerant recovery is complete and no refrigerant leakage is detected by the detector (45A) (4020).

[0246] The air conditioner (1) may further include a pressure reducing pipe (241) that is connected to the low-pressure gas pipe (22) so as to connect the upstream and downstream of the low-pressure gas pipe (22) with respect to the flow direction of the refrigerant in the low-pressure gas pipe (22) based on the low-pressure valve (222). The opening / closing valve (200) may further include a pressure reducing valve (242) that is provided to open and close the pressure reducing pipe (241) and is controlled by the control unit (110). The control unit (110) may control (5010) the pressure reducing valve (242) to close the pressure reducing pipe (241) based on the detection of a refrigerant leak by the detector (45A).

[0247] One end of the above pressure reducing pipe (241) may be connected upstream of the low pressure valve (222) with respect to the flow direction of the refrigerant in the low pressure gas pipe (22). The air conditioner (1) may further include a check valve (223) arranged upstream of one end of the above pressure reducing pipe (241) with respect to the flow direction of the refrigerant in the low pressure gas pipe (22).

[0248] A multi-air conditioner (3) according to one embodiment includes an outdoor unit (10), a first indoor unit (40A) and a second indoor unit (40B) which are spaced apart from each other and each include a detector (45A) for detecting a refrigerant leak and are connected to the outdoor unit (10). The multi-air conditioner (3) includes a heating and cooling switching device (30) which includes a control unit (110) which controls the first indoor unit (40A) and the second indoor unit (40B) so that the first indoor unit (40A) and the second indoor unit (40B) operate in a cooling or heating mode. The heating and cooling switching device (30) includes a high-pressure gas pipe (21) through which refrigerant is supplied from the outdoor unit (10) to the first indoor unit (40A) or the second indoor unit (40B). The above-described heating and cooling switching device (30) includes a low-pressure gas pipe (22) provided to recover refrigerant from the first indoor unit (40A) or the second indoor unit (40B) to the outdoor unit (10). The heating and cooling switching device (30) includes a liquid pipe (23) provided to supply refrigerant from the outdoor unit (10) to the first indoor unit (40A) or the second indoor unit (40B) or to recover refrigerant from the first indoor unit (40A) or the second indoor unit (40B) to the outdoor unit (10). The heating and cooling switching device (30) includes an opening / closing valve (200) provided to open / close the high-pressure gas pipe (21), the low-pressure gas pipe (22), and the liquid pipe (23). The above control unit (110) controls the opening / closing valve (200) so that the refrigerant is recovered from the first indoor unit (40A) or the second indoor unit (40B) to the outdoor unit (10) through the low-pressure gas pipe (22) based on the detection of a refrigerant leak by the detector (45A).

[0249] The high-pressure gas pipe (21) may include a first high-pressure gas pipe (211A) connected to the first indoor unit (40A). The low-pressure gas pipe (22) may include a first low-pressure gas pipe (221A) connected to the first indoor unit (40A). The liquid pipe (23) may include a first liquid pipe (231A) connected to the first indoor unit (40A). The opening / closing valve (200) may include a first high-pressure valve (212A) provided to open / close the first high-pressure gas pipe (211A). The opening / closing valve (200) may include a first low-pressure valve (222A) provided to open / close the first low-pressure gas pipe (221A). The above-mentioned opening / closing valve (200) may include a first liquid pipe valve (232A) provided to open and close the first liquid pipe (231A). The control unit (110) may control the first high-pressure valve (212A), the first low-pressure valve (222A), and the first liquid pipe valve (232A), respectively.

[0250] When the first indoor unit (40A) is operating in cooling mode, the first high-pressure gas pipe (211A) may be closed and the first low-pressure gas pipe (221A) and the first liquid pipe (231A) may be arranged to be open (1010). The control unit (110) may control (1030) the first liquid pipe valve (232A) to close the first liquid pipe (231A) and block the flow of refrigerant to the first indoor unit (40A) based on the detection (1020) of a refrigerant leak by the detector (45A) of the first indoor unit (40A) when the first indoor unit (40A) is in cooling mode, and may control (1050) the first low-pressure valve (222A) to close the first low-pressure gas pipe (221A) based on the detection (1040) of no refrigerant leak by the detector (45A) of the first indoor unit (40A) when the refrigerant on the first indoor unit (40A) side is recovered to the outdoor unit (10) through the first low-pressure gas pipe (221A).

[0251] When the first indoor unit (40A) is operating in heating mode, the first low-pressure gas pipe (221A) may be closed and the first high-pressure gas pipe (211A) and the first liquid pipe (231A) may be arranged to be open (2010). The control unit (110) controls the first high-pressure valve (212A) to close the first high-pressure gas pipe (211A) based on the detection (2020) of refrigerant leakage from the detector (45A) of the first indoor unit (40A) when the first indoor unit (40A) is in heating mode (2030), to block the flow of refrigerant to the first indoor unit (40A) by closing the first high-pressure gas pipe (211A), to control the first liquid pipe valve (232A) to close the first liquid pipe (231A) (2040), and to open the first low-pressure gas pipe (221A) so that the refrigerant on the first indoor unit (40A) side is recovered to the outdoor unit (10) (2050), and the refrigerant on the first indoor unit (40A) side is returned to the first The first low-pressure valve (222A) can be controlled (2070) to close the first low-pressure gas pipe (221A) based on the fact that the refrigerant is recovered to the outdoor unit (10) through the low-pressure gas pipe (221A) and that no refrigerant leak is detected (2060) by the detector (45A) of the first indoor unit (40A).

[0252] When the first indoor unit (40A) is not in operation, the first high-pressure gas pipe (211A), the first low-pressure gas pipe (221A), and the first liquid pipe (231A) may be arranged to be closed (3010). The control unit (110) may control the first low-pressure valve (222A) to open the first low-pressure gas pipe (221A) and allow the refrigerant on the first indoor unit (40A) side to be recovered to the outdoor unit (10) based on the detection (3020) of a refrigerant leak by the detector (45A) of the first indoor unit (40A) when the first indoor unit (40A) is not in operation (3030).

[0253] An air conditioner (1) according to one embodiment includes an outdoor unit (10) including a compressor (11A, 11B) that compresses and discharges a refrigerant. The air conditioner (1) includes a detector (45A) that detects a leak of the refrigerant and an indoor unit (40A) connected to the outdoor unit (10). The air conditioner (1) includes a high-pressure gas pipe (21) that connects the compressor (11A, 11B) and the indoor unit (40A) so that the refrigerant discharged from the compressor (11A, 11B) is supplied to the indoor unit (40A). The air conditioner (1) includes a low-pressure gas pipe (22) that is provided so that the refrigerant is recovered from the indoor unit (40A) to the compressor (11A, 11B). The air conditioner (1) includes a liquid pipe (23) provided to supply refrigerant from the outdoor unit (10) to the indoor unit (40A) or to recover refrigerant from the indoor unit (40A) to the outdoor unit (10). The air conditioner (1) includes an on-off valve (200) provided to open and close the high-pressure gas pipe (21), the low-pressure gas pipe (22), and the liquid pipe (23). The air conditioner (1) includes a control unit (110) that is electrically connected to the detector (45A) and the on-off valve (200), and controls the on-off valve (200) so that the refrigerant on the indoor unit (40A) side is recovered to the compressor (11A, 11B) based on the detection of refrigerant leakage by the detector (45A).

[0254] According to the idea of ​​the present disclosure, in case of a refrigerant leak, the refrigerant can be prevented from flowing toward the indoor unit placed in the room where the user stays, thereby improving the safety of use.

[0255] According to the idea of ​​the present disclosure, in case of a refrigerant leak, the refrigerant remaining in the indoor unit placed in the room where the user stays can be recovered to the outdoor unit, thereby improving the safety of use.

[0256] The effects that can be obtained from the present disclosure are not limited to the effects mentioned above, and other effects that are not mentioned can be clearly understood by a person having ordinary skill in the art to which the present disclosure belongs from the description below.

[0257] The above illustrates and describes specific embodiments. However, the invention is not limited to the above-described embodiments, and those skilled in the art will readily appreciate that various modifications and implementations can be made without departing from the spirit and scope of the invention as set forth in the claims below.

Claims

1. Outdoor unit; An indoor unit including a detector for detecting refrigerant leakage and connected to the outdoor unit; A high-pressure gas pipe provided to supply refrigerant from the outdoor unit to the indoor unit; A low-pressure gas pipe provided to recover refrigerant from the indoor unit to the outdoor unit; A liquid pipe provided to supply refrigerant from the outdoor unit to the indoor unit or to recover refrigerant from the indoor unit to the outdoor unit; An opening / closing valve provided to open / close the high-pressure gas pipe, the low-pressure gas pipe, and the liquid pipe; and A control unit electrically connected to the above detector and the above opening / closing valve; An air conditioner in which the control unit controls the opening / closing valve so that refrigerant is recovered from the indoor unit to the outdoor unit through the low-pressure gas pipe based on the detection of refrigerant leakage by the detector.

2. In paragraph 1, The above opening / closing valve, A high pressure valve provided to open and close the high pressure gas pipe, A low-pressure valve provided to open and close the above low-pressure gas pipe, and Including a liquid pipe valve provided to open and close the liquid pipe, An air conditioner in which the above control unit controls the high pressure valve, the low pressure valve, and the liquid pipe valve, respectively.

3. In paragraph 2, When the indoor unit is operating in cooling mode, the high-pressure gas pipe is closed and the low-pressure gas pipe and the liquid pipe are opened. An air conditioner in which the control unit controls the liquid pipe valve to close the liquid pipe and block the flow of refrigerant to the indoor unit based on the detection of refrigerant leakage by the detector while the indoor unit is operating in cooling mode.

4. In paragraph 3, The refrigerant on the indoor unit side is arranged to be returned to the outdoor unit through the low-pressure gas pipe. An air conditioner in which the control unit controls the low-pressure valve to close the low-pressure gas pipe based on the completion of refrigerant recovery and no refrigerant leakage is detected by the detector.

5. In paragraph 2, When the indoor unit is operating in heating mode, the low-pressure gas pipe is closed and the high-pressure gas pipe and the liquid pipe are opened. An air conditioner in which the control unit controls the high-pressure valve to close the high-pressure gas pipe and block the flow of refrigerant to the indoor unit based on the detection of a refrigerant leak by the detector while the indoor unit is operating in heating mode.

6. In paragraph 5, An air conditioner in which the control unit controls the liquid pipe valve to close the liquid pipe based on the detection of refrigerant leakage by the detector while the indoor unit is operating in heating mode.

7. In paragraph 6, An air conditioner in which the control unit controls the low-pressure valve to open the low-pressure gas pipe so that the refrigerant on the indoor unit side is recovered to the outdoor unit based on the detection of a refrigerant leak by the detector while the indoor unit is operating in heating mode.

8. In paragraph 7, An air conditioner in which the control unit controls the low-pressure valve to close the low-pressure gas pipe based on the completion of refrigerant recovery and no refrigerant leakage is detected by the detector.

9. In paragraph 2, When the above indoor unit is not operating, the high-pressure gas pipe, the low-pressure gas pipe, and the liquid pipe are arranged to be closed. An air conditioner in which the control unit controls the low-pressure valve to open the low-pressure gas pipe so that the refrigerant on the indoor unit side is recovered to the outdoor unit based on the detection of refrigerant leakage by the detector when the indoor unit is not operating.

10. In paragraph 2, Further comprising a check valve positioned upstream of the low-pressure valve with respect to the flow direction of the refrigerant in the low-pressure gas pipe; An air conditioner in which the above check valve is provided to prevent refrigerant flowing in the low-pressure gas pipe from flowing from the outdoor unit to the indoor unit.

11. In paragraph 2, Further comprising a connecting pipe connecting the liquid pipe and the heat exchanger of the indoor unit, including one end connected to the liquid pipe and the other end connected to the heat exchanger of the indoor unit; The above opening / closing valve further includes a connecting pipe valve which is provided to open / close the connecting pipe and is controlled by the control unit; An air conditioner in which the control unit controls the connection pipe valve to open the connection pipe based on the detection of a refrigerant leak by the detector.

12. In paragraph 11, The refrigerant on the indoor unit side is arranged to be returned to the outdoor unit through the low-pressure gas pipe. An air conditioner in which the control unit controls the low-pressure valve to close the low-pressure gas pipe and controls the connection pipe valve to close the connection pipe based on the completion of refrigerant recovery and no refrigerant leakage detected by the detector.

13. In paragraph 2, It further includes a pressure reducing pipe that is connected to the low-pressure gas pipe to connect the upstream and downstream of the low-pressure gas pipe based on the low-pressure valve with respect to the flow direction of the refrigerant in the low-pressure gas pipe; The above opening / closing valve further includes a pressure reducing valve which is provided to open / close the pressure reducing pipe and is controlled by the control unit; An air conditioner in which the control unit controls the pressure reducing valve to close the pressure reducing tube based on the detection of a refrigerant leak by the detector.

14. In paragraph 13, One end of the above pressure reducing pipe is connected upstream of the low pressure valve with respect to the flow direction of the refrigerant in the low pressure gas pipe. An air conditioner further comprising a check valve disposed upstream of one end of the pressure reducing pipe with respect to the flow direction of the refrigerant in the low-pressure gas pipe.

Images