KR20240169878A - Air conditioner and multi airconditioner having the same - Google Patents

Abstract

An air conditioner includes an outdoor unit and an indoor unit connected to the outdoor unit. The air conditioner includes a refrigerant pipe that connects the outdoor unit and the indoor unit to allow refrigerant to flow. The refrigerant pipe includes a high-pressure gas pipe that supplies refrigerant to the indoor unit, and a high-pressure pipe valve that is provided in the high-pressure gas pipe. In addition, the refrigerant pipe includes a low-pressure gas pipe that allows refrigerant to be recovered to the outdoor unit, and a low-pressure pipe valve that is provided in the low-pressure gas pipe. The refrigerant pipe includes a liquid pipe, a liquid pipe valve that is provided in the liquid pipe, a liquid pipe connection pipe that is connected to the indoor unit by being combined with the liquid pipe, and a liquid pipe connection pipe valve that is provided in the liquid pipe connection pipe. In addition, the refrigerant pipe includes a bypass pipe that connects the low-pressure gas pipe and the liquid pipe, and a bypass valve that is provided in the bypass pipe. The liquid pipe includes a liquid refrigerant flow section defined as a section between the liquid pipe valve and the liquid pipe connection pipe valve, and the bypass pipe is provided so that one end is combined with the liquid refrigerant flow section, and the other end is combined with the low-pressure gas pipe.

Description

AIR CONDITIONER AND MULTI AIRCONDITIONER HAVING THE SAME

The present disclosure relates to an air conditioner and a multi-air conditioner including the same, and more specifically, to an air conditioner preventing a liquid seal phenomenon and a multi-air conditioner including the same.

An air conditioner is a device for cooling or heating an indoor space. When an indoor space is divided into multiple spaces, an air conditioner may be installed for cooling or heating each indoor space.

A multi-air conditioner can have multiple indoor units connected to one outdoor unit. Multiple indoor units are installed in each indoor space, so that the temperature of each indoor space can be individually controlled according to the user's convenience.

One aspect of the present disclosure provides an air conditioner that prevents a liquid seal phenomenon in a liquid pipe when refrigerant flow is blocked, and a multi-air conditioner including the same.

One aspect of the present disclosure provides an air conditioner that lowers the pressure of a liquid pipe through a bypass pipe combined with a liquid pipe, and a multi-air conditioner including the same.

One aspect of the present disclosure provides an air conditioner that reduces refrigerant leakage in a refrigerant pipe on an indoor unit side when refrigerant leakage occurs, and a multi-air conditioner including the same.

One aspect of the present disclosure provides an air conditioner and a multi-air conditioner including the same, which reduces refrigerant leakage in a refrigerant pipe on the indoor unit side by installing a check valve when refrigerant leakage occurs.

The technical problems to be achieved in this document are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which the present invention belongs from the description below.

An air conditioner according to the invention includes an outdoor unit. The air conditioner includes an indoor unit connected to the outdoor unit. The air conditioner includes a refrigerant pipe connected to the outdoor unit and the indoor unit to allow refrigerant to flow. The refrigerant pipe includes a high-pressure gas pipe connected to supply refrigerant to the indoor unit. The refrigerant pipe includes a high-pressure pipe valve connected to the high-pressure gas pipe. The refrigerant pipe includes a low-pressure gas pipe connected to recover refrigerant to the outdoor unit. The refrigerant pipe includes a low-pressure pipe valve connected to the low-pressure gas pipe. The refrigerant pipe includes a liquid pipe. The refrigerant pipe includes a liquid pipe valve connected to the liquid pipe. The refrigerant pipe includes a liquid pipe connection pipe connected to the indoor unit by being joined to the liquid pipe. The refrigerant pipe includes a liquid pipe connection pipe valve connected to the liquid pipe connection pipe. The refrigerant pipe includes a bypass pipe connecting the low-pressure gas pipe and the liquid pipe. The refrigerant pipe includes a bypass valve connected to the bypass pipe. The above liquid pipe includes a liquid refrigerant flow section defined as a section between the liquid pipe valve and the liquid pipe connecting valve. The bypass pipe is provided so that one end is connected to the liquid refrigerant flow section and the other end is connected to the low-pressure gas pipe.

A multi-air conditioner according to the invention includes an outdoor unit. The multi-air conditioner includes an indoor unit connected to the outdoor unit. The indoor unit includes a first indoor unit. The indoor unit includes a second indoor unit spaced apart from the first indoor unit. The multi-air conditioner includes a heating and cooling switch including a portion of a refrigerant pipe provided to connect the outdoor unit and the indoor unit and to allow refrigerant to flow. The refrigerant pipe includes a high-pressure gas pipe provided to supply refrigerant to the indoor unit. The refrigerant pipe includes a high-pressure pipe valve provided in the high-pressure gas pipe. The refrigerant pipe includes a low-pressure gas pipe provided to recover refrigerant to the outdoor unit. The internal pipe includes a low-pressure pipe valve provided in the low-pressure gas pipe. The refrigerant pipe includes a liquid pipe. The refrigerant pipe includes a liquid pipe valve provided in the liquid pipe. The refrigerant pipe includes a liquid pipe connection pipe that is combined with the liquid pipe and connected to the indoor unit. The refrigerant pipe includes a liquid pipe connection pipe valve provided in the liquid pipe connection pipe. The above refrigerant pipe includes a bypass pipe connecting the low-pressure gas pipe and the liquid pipe. The refrigerant pipe includes a bypass valve provided in the bypass pipe. The liquid pipe includes a liquid refrigerant flow section defined as a section between the liquid pipe valve and the liquid pipe connection valve. The bypass pipe is provided so that one end is joined to the liquid refrigerant flow section. The bypass pipe is provided so that the other end is joined to the low-pressure gas pipe. The heating and cooling switch includes a control unit that controls the high-pressure pipe valve, the low-pressure pipe valve, and the liquid pipe valve to be closed so as to block the high-pressure gas pipe, the low-pressure gas pipe, and the liquid pipe connected to the first indoor unit when the operation of the first indoor unit is stopped.

Figure 1 is a drawing schematically illustrating an air conditioner according to one embodiment.
Figure 2 is a schematic drawing showing the state in which the pressure regulating valve opens and refrigerant flows in the pressure regulating pipe when the air conditioner of Figure 1 switches from heating mode to cooling mode.
Figure 3 is a schematic diagram illustrating the air conditioner of Figure 1 in operation when switched to cooling mode.
FIG. 4 is a drawing schematically illustrating a state in which a refrigerant pipe is blocked when a refrigerant leak occurs in an air conditioner according to one embodiment.
Figure 5 is a schematic drawing showing the air conditioner of Figure 4 with the bypass valve open and refrigerant flowing in the bypass pipe.
FIG. 6 is a drawing schematically illustrating a state in which a refrigerant pipe is blocked when a refrigerant leak occurs in an air conditioner according to one embodiment.
FIG. 7 is a drawing schematically illustrating the structure of a multi-air conditioner according to one embodiment.
FIG. 8 is an enlarged view showing a portion of a heating/cooling switch and an indoor unit of a multi-air conditioner according to one embodiment.
FIG. 9 is a schematic drawing showing a state in which a refrigerant pipe connected to a first indoor unit in FIG. 8 is blocked, and a state in which refrigerant flows in a pressure regulating pipe connected to a second indoor unit when the second indoor unit switches from heating mode to cooling mode.
Figure 10 is a schematic drawing showing the refrigerant flowing in a bypass pipe connected to the first indoor unit in Figure 9 and the second indoor unit switching to cooling mode and operating.
Fig. 11 is an enlarged view showing a portion of a heating/cooling switch and an indoor unit of a multi-air conditioner according to one embodiment.

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

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

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

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" can include any one of the items listed together in that phrase, or all possible combinations of them.

The term "and/or" includes any combination of multiple related described elements or any one of multiple related described elements.

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

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.

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

When a component is said to be “connected,” “coupled,” “supported,” or “contacted” 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.

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.

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.

According to one embodiment, the 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 is circulated along a compressor, a first heat exchanger, an expansion device, and a second heat exchanger. All components of the heat pump device may be built into a single housing forming the exterior of the air conditioner, and a window air conditioner or a portable air conditioner corresponds to such an air conditioner. On the other hand, some components of the heat pump device may be built into a plurality of housings forming a single air conditioner, and this includes a wall-mounted air conditioner, a stand-alone air conditioner, a system air conditioner, etc.

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 provided such that one outdoor unit and one indoor unit are connected via a refrigerant pipe. For example, the air conditioner may be provided such that one outdoor unit is connected to two or more indoor units via refrigerant pipes. For example, the air conditioner may be provided such that two or more outdoor units and two or more indoor units are connected via a plurality of refrigerant pipes.

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 unit or the indoor unit, and the outdoor unit and the indoor unit can operate simultaneously or sequentially in response to the user input.

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

The outdoor heat exchanger can perform heat exchange between the refrigerant and the outdoor air by utilizing the phase change of the refrigerant (e.g., evaporation or condensation). For example, while the refrigerant condenses in the outdoor heat exchanger, the refrigerant can release heat to the outdoor air, and while the refrigerant flowing in the outdoor heat exchanger evaporates, the refrigerant can absorb heat from the outdoor air.

Indoor units are installed indoors. For example, indoor units can be classified into ceiling-mounted indoor units, stand-alone indoor units, and wall-mounted indoor units depending on how they are placed. For example, ceiling-mounted indoor units can be classified into 4-way indoor units, 1-way indoor units, and duct-type indoor units depending on how air is discharged.

Likewise, the indoor heat exchanger can perform heat exchange between the refrigerant and indoor air by utilizing the phase change of the refrigerant (e.g., evaporation or condensation). For example, while the refrigerant evaporates in the indoor unit, the refrigerant can absorb heat from the indoor air, and the indoor space can be cooled by blowing the cooled indoor air while passing through the cooled indoor heat exchanger. Also, while the refrigerant condenses in the indoor heat exchanger, the refrigerant can release heat to the indoor air, and the indoor space can be heated by blowing the heated indoor air while passing through the high-temperature indoor heat exchanger.

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

The refrigerant may be circulated through the refrigerant pipes in the order of a compressor, an outdoor heat exchanger, an expansion device, and an indoor heat exchanger, or in the order of a compressor, an indoor heat exchanger, an expansion device, and an outdoor heat exchanger.

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

For example, in the case where an air conditioner has one outdoor unit connected to two or more indoor units through refrigerant pipes, the refrigerant can flow to multiple indoor units through refrigerant pipes branching from the outdoor unit. The refrigerants discharged from multiple indoor units can be combined and circulated to the outdoor unit. For example, multiple indoor units can be directly connected to one outdoor unit in parallel through separate refrigerant pipes.

The multiple indoor units can be operated independently according to the operation mode set by the user. That is, some of the multiple indoor units can be operated in cooling mode while others can be operated in heating mode at the same time. At this time, the refrigerant can be selectively introduced into each indoor unit in a high or low pressure state along a designated circulation path through a flow switching valve described later, and discharged and circulated to the outdoor unit.

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 before branching off again at some point and flowing into multiple indoor units.

The plurality of outdoor units may be driven or at least some of them may not be driven depending on the operating load according to the operating amount of the plurality of indoor units. At this time, the refrigerant may be arranged to be introduced into the outdoor unit that is selectively driven through the refrigerant diverter valve and circulated. The air conditioner may include an expansion device to reduce the pressure of the refrigerant introduced into the heat exchanger. For example, the expansion device may be placed inside the indoor unit or the outdoor unit, or may be placed in both.

The expansion device can lower the temperature and pressure of the refrigerant by, for example, using the throttling effect. The expansion device can include an orifice that can reduce the cross-sectional area of the passage. The refrigerant passing through the orifice can have its temperature and pressure lowered.

The expansion device can 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 in a partially open state to the cross-sectional area of the valve's flow path in a fully open state). Depending on the opening ratio of the electronic expansion valve, the amount of refrigerant passing through the expansion device can be controlled.

The air conditioner may further include a flow diverter valve disposed on the refrigerant circulation path. The flow diverter valve may include, for example, a 4-way valve. The flow diverter valve may determine the circulation path of the refrigerant depending on the operating mode of the indoor unit (for example, cooling operation or heating operation). The flow diverter valve may be connected to the discharge port of the compressor.

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

The accumulator can separate the refrigerant liquid from the refrigerant gas when the refrigerant, which is a 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.

An outdoor fan may be provided 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.

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 environment sensor. The outdoor unit sensor may be placed at any location inside or outside the outdoor unit. For example, the outdoor unit sensor may include a temperature sensor for detecting air temperature around the outdoor unit, a humidity sensor for detecting air humidity around the outdoor unit, a refrigerant temperature sensor for detecting refrigerant temperature of a refrigerant pipe passing through the outdoor unit, or a refrigerant pressure sensor for detecting refrigerant pressure of a refrigerant pipe passing through the outdoor unit.

An outdoor unit of an air conditioner may include an outdoor unit communication unit. The outdoor unit communication unit may be provided 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 plenum 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 from an outdoor unit sensor to the control unit of the indoor unit through the outdoor unit communication unit.

An indoor unit of an 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.

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

The indoor unit of the air conditioner may include a filter provided to filter foreign substances in the air flowing into the housing through the intake port.

The housing may include an exhaust port. Air flowing within the housing may be exhausted to the exterior of the housing through the exhaust port.

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 a blade positioned on the exhaust port. For example, the airflow guide may include an auxiliary fan for controlling the exhaust airflow. Without being limited thereto, the airflow guide may be omitted.

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.

The blower may include an indoor fan and a fan motor. For example, the indoor fan may include an axial fan, a diffusion fan, a crossflow fan, or a centrifugal fan.

The 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 introduced through the intake, or may transfer heat to air introduced 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 area.

The indoor unit of the air conditioner may include a drain tray arranged 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.

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 may directly input setting data (e.g., desired indoor temperature, operation mode setting of cooling/heating/dehumidification/air purification, outlet selection setting, and/or air volume setting) through the input interface.

The input interface may 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 part of a wall). A user may input setting data regarding the operation of the air conditioner by operating the wired remote controller. An electrical signal corresponding to the setting data acquired 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 input setting data regarding the operation of the air conditioner remotely using the wireless remote controller. The setting data input through the wireless remote controller may be transmitted to the input interface as an infrared signal.

In addition, 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 setting of cooling/heating/dehumidification/air purification, outlet selection setting, and/or wind speed setting) may be transmitted to the indoor unit control unit described below. In one example, the setting data acquired through the input interface may be transmitted to the outside, i.e., to an outdoor unit or a server, through an indoor unit communication unit described below.

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

An indoor unit of an air conditioner may include an indoor unit sensor. The indoor unit sensor may be an environmental sensor disposed 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 disposed 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 an inlet, an intermediate, and/or an outlet temperature of a refrigerant pipe passing through the indoor heat exchanger.

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.

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 wirelessly communicating with another device. 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.

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, a UWB (ultrawideband) communication module, an Ant+ communication module, a microwave (uWave) communication module, etc.

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 a wireless signal with at least one of a base station, an external terminal, and a server on a mobile communication network.

The indoor unit communication unit can communicate with external devices such as a server, mobile devices, and other home appliances through a surrounding 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 can include an indoor unit control unit that controls components of the indoor unit including a blower, etc. The outdoor unit of the air conditioner can 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 a control signal generated by the outdoor unit control unit to the indoor unit communication unit, or transmit a control signal 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 in both directions. The outdoor unit and the indoor unit can transmit and receive various signals generated during the operation of the air conditioner.

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 refrigerant diverting 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 for adjusting the opening degree of the expansion valve. Under the control of the outdoor unit control unit, the refrigerant can be circulated along a refrigerant circulation circuit including the compressor, the refrigerant diverting valve, the outdoor heat exchanger, the expansion valve, and the indoor heat exchanger.

Various temperature sensors included in the outdoor unit and the indoor unit can transmit electrical signals corresponding to the detected temperature to the outdoor unit control unit and/or the indoor unit control unit, respectively. For example, humidity sensors included in the outdoor unit and the indoor unit can transmit electrical signals corresponding to the detected humidity to the outdoor unit control unit and/or the indoor unit control unit, respectively.

The indoor unit control unit can obtain user input from a user device, including a mobile device, through the indoor unit communication unit, and can obtain user input directly or through a remote controller through an input interface. 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 about the received user input to the outdoor unit control unit of the outdoor unit.

The outdoor unit control unit can control the configurations of the outdoor unit, including the compressor, based on information about the 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 dehumidifying operation, is received from the indoor unit, the outdoor unit control unit can control the configurations of the outdoor unit so that the operation of the air conditioner corresponding to the selected operation mode is performed.

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.

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 operation, heating operation, dehumidification operation, and/or defrosting operation of the air conditioner. The memory can include volatile memory such as S-RAM (Static Random Access Memory, S-RAM) and D-RAM (Dynamic Random Access Memory) for temporarily storing data. In addition, the memory can include nonvolatile memory such as ROM (Read Only Memory), EPROM (Erasable Programmable Read Only Memory), and EEPROM (Electrically Erasable Programmable Read Only Memory) for long-term storage of data.

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

An indoor unit of an air conditioner may include an output interface. The output interface is electrically connected to an indoor unit control unit and may 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 operation mode, wind direction, wind volume, and temperature selected by a user input may be output. In addition, the output interface may output sensing information obtained from an indoor unit sensor or an outdoor unit sensor, and warning/error messages.

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

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

Fig. 1 is a schematic drawing of an air conditioner according to one embodiment. Fig. 2 is a schematic drawing of a pressure regulating valve (242) being opened and refrigerant flowing in a pressure regulating pipe when the air conditioner of Fig. 1 is switched from a heating mode to a cooling mode. Fig. 3 is a schematic drawing of a state in which the air conditioner of Fig. 1 is switched to a cooling mode and operates.

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.

The air conditioner (1) 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 include an indoor heat exchanger (42). The indoor heat exchanger (42) may be provided so that refrigerant passing through the indoor heat exchanger (42) undergoes heat exchange.

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

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

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

The refrigerant pipe (20) may include a high-pressure pipe valve (212). The high-pressure pipe valve (212) may be provided in the high-pressure gas pipe (21). When the high-pressure pipe valve (212) is closed, the high-pressure gas pipe (21) is blocked, so that the refrigerant may not flow in the high-pressure gas pipe (21).

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

The refrigerant pipe (20) may include a low-pressure pipe valve (222). The low-pressure pipe valve (222) may be provided in the low-pressure gas pipe (22). When the low-pressure pipe valve (222) is closed, the low-pressure gas pipe (22) is blocked, so that the refrigerant may not flow in the low-pressure gas pipe (22).

The refrigerant pipe (20) may include a liquid pipe (23). The liquid pipe (23) may be provided to connect the indoor unit (40) and the outdoor unit (10). A liquid refrigerant may flow in the liquid pipe (23). Through the liquid pipe (23), the refrigerant may be supplied from the outdoor unit (10) to the indoor unit (40) or recovered from the indoor unit (40) to the outdoor unit (10).

The refrigerant pipe (20) 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 the refrigerant may not flow in the liquid pipe (23).

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

The refrigerant pipe (20) may include a control valve (242). The control valve (242) may be provided in the pressure regulating pipe (241).

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

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.

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.

The outdoor unit (10) may include an outdoor blower fan (16). The outdoor blower fan (16) may be provided on the outdoor heat exchanger (15) side. The outdoor blower fan (16) may be installed so that air on the outdoor heat exchanger (15) side is blown out to the outside.

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 arranged to depressurize and expand the refrigerant.

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).

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).

The four-way 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).

The outdoor unit (10) may include a high-pressure branch pipe (14). The high-pressure branch pipe (14) may be arranged to be connected to the 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 the 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) for preventing 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 a high pressure branch pipe (14) through an electronic valve (14A).

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 a downstream side from the accumulator (19). The third port (13C) may be arranged so that the refrigerant may be circulated to the compressor (11A, 11B) through the third port (13C) and the accumulator (19).

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).

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).

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

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

When the indoor unit (40) 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 pipe 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 (40) through the gas pipe connection pipe (261). At this time, since the low-pressure pipe valve (222) is in a closed state, the refrigerant may flow into the indoor unit (40). The refrigerant that has flowed into the indoor unit (40) may change into a high-temperature, high-pressure liquid state through heat exchange with the indoor heat exchanger (42). After the heat exchange, the indoor blower fan (41) may blow air from the indoor heat exchanger (42) side into the occupied space to heat the occupied space. The refrigerant that has passed through the indoor heat exchanger (42) can flow into the liquid pipe connection pipe (43). At this time, the liquid pipe connection pipe valve (44) may be in an open state. The refrigerant that has flowed into the liquid pipe connection pipe (43) 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 flow 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 called a heating cycle.

An air conditioner (1) in heating operation can change the mode to cooling operation. When an air conditioner (1) in heating operation changes to cooling operation, the high-pressure gas pipe (21) can be arranged to be closed and the low-pressure gas pipe (22) to be opened. At this time, since 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 pipe 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 pipe valve (222) due to the pressure acting on the low-pressure pipe valve (222). In order to prevent noise in the low-pressure pipe valve (222) due to the pressure acting on the low-pressure pipe valve (222), the control valve (242) can be controlled to be opened. When the regulating valve (242) is opened, the refrigerant can flow from one end of the pressure regulating pipe (241) to the other end of the pressure regulating pipe (241) through the pressure regulating pipe (241). Accordingly, the pressure difference between the two sides of the low-pressure gas pipe (22) with respect to the low-pressure pipe valve (222) is reduced, so that noise generated from the low-pressure pipe valve (222) can be reduced.

During the cooling operation of the indoor unit (40), 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 liquid pipe connecting pipe (43). At this time, the refrigerant may change to a low temperature, low pressure liquid state as it passes through the liquid pipe connecting pipe valve (44). That is, the liquid pipe connecting pipe valve (44) may perform the role of an expansion valve. The refrigerant passing through the liquid pipe connection pipe (43) can flow into the indoor unit (40). The refrigerant flowing into the indoor unit (40) can change into a low-temperature, low-pressure gaseous state through heat exchange with the indoor heat exchanger (42). After the heat exchange, the indoor blower fan (41) can blow air from the indoor heat exchanger (42) side into the occupied space to cool the occupied space. The refrigerant passing through the indoor heat exchanger (42) can flow into the low-pressure gas pipe (22) through the gas pipe connection pipe (261). The low-pressure pipe valve (222) can be in an open state. At this time, since the high-pressure pipe 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.

The air conditioner (1) may include a control unit. The control unit may control the flow of refrigerant in the refrigerant pipe (20). That is, the control unit may control the opening and closing of the high-pressure pipe valve (212). The control unit may control the opening and closing of the low-pressure pipe valve (222). The control unit may control the opening and closing of the liquid pipe valve (232). The control unit may control the opening and closing of the liquid pipe connecting pipe (43) valve. The control unit may control the opening and closing of the regulating valve (242). The control unit may control the opening and closing of the four-way valve (13).

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

Fig. 4 is a schematic drawing showing a state in which a refrigerant pipe is blocked when a refrigerant leak occurs in an air conditioner according to one embodiment. Fig. 5 is a schematic drawing showing a state in which a bypass valve is opened and refrigerant flows in a bypass pipe in the air conditioner of Fig. 4. Descriptions of content that overlaps with the above content are omitted below.

Referring to FIGS. 4 and 5, the refrigerant flowing in the refrigerant pipe (20) may leak outside the refrigerant pipe (20). That is, the refrigerant may leak from the refrigerant pipe (20). There may be various causes for the refrigerant to leak. For example, the refrigerant may leak due to damage to the refrigerant pipe (20).

In the event of a refrigerant leak, the air conditioner (1) may be arranged to block the flow of refrigerant to the indoor unit (40). More specifically, in the event of a refrigerant leak, the high-pressure pipe valve (212), the low-pressure pipe valve (222), the liquid pipe valve (232), and the liquid pipe connection pipe (43) valves may be closed. In general, since there are users in the occupied space where the indoor unit (40) is installed, this may be to prevent safety accidents due to refrigerant leakage from the refrigerant pipe (20) on the indoor unit (40) side.

If the refrigerant flow is blocked, the refrigerant may not flow to the indoor unit (40). That is, the refrigerant may be provided in a stopped state in the refrigerant pipe (20) arranged on the indoor unit (40) side. Through this, additional refrigerant inflow to the indoor unit (40) side can be blocked, thereby minimizing safety accidents due to refrigerant leakage.

The pressure regulating pipe (241) may include a first check valve (243). The first check valve (243) may be positioned upstream of the regulating valve (242) with respect to the flow direction of the refrigerant in the pressure regulating pipe (241). Even if the regulating valve (242) is closed so as to block the flow of the refrigerant in the pressure regulating pipe (241), there may be cases where the refrigerant flows toward the indoor unit (40) in the pressure regulating pipe (241). In order to prevent such additional refrigerant inflow, the first check valve (243) may be provided to block the refrigerant in the pressure regulating pipe (241) from flowing from the other end of the pressure regulating pipe (241) to one end of the pressure regulating pipe (241). That is, the first check valve (243) may be provided to block the refrigerant from flowing in the direction toward the indoor unit (40).

The low-pressure gas pipe (22) may include a second check valve (223). The second check valve (223) may be positioned upstream of the low-pressure pipe valve (222) with respect to the flow direction of the refrigerant in the low-pressure gas pipe (22). Even if the low-pressure pipe valve (222) is closed so as to block the flow of the refrigerant in the low-pressure gas pipe (22), there may be cases where the refrigerant flows toward the indoor unit (40) in the low-pressure gas pipe (22). In order to prevent such additional refrigerant inflow, the second check valve (223) may be provided to block the refrigerant in the low-pressure gas pipe (22) from flowing toward the indoor unit (40). That is, the second check valve (223) may be provided to block the refrigerant from flowing in the direction of the indoor unit (40).

The liquid pipe (23) may include a liquid refrigerant flow section (231) defined as a section between a liquid pipe valve (232) and a liquid pipe connecting valve (44). When the refrigerant flow is blocked, the liquid refrigerant flow section (231) may be closed. A liquid refrigerant may be accommodated in the liquid refrigerant flow section (231).

The refrigerant pipe (20) may include a bypass pipe (251). The bypass pipe (251) may connect the low-pressure gas pipe (22) and the liquid pipe (23). More specifically, one end of the bypass pipe (251) may be joined to the liquid refrigerant flow section (231). The bypass pipe (251) may be arranged so that the other end is joined to the low-pressure gas pipe (22). The other end of the bypass pipe (251) may be arranged downstream of the low-pressure pipe valve (222) with respect to the flow direction of the refrigerant in the low-pressure gas pipe (22).

The refrigerant pipe (20) may include a bypass valve (252). The bypass valve (252) may be provided in the bypass pipe (251). The bypass valve (252) may be a pressure regulating valve (242, PRESSURE REGULATING VALVE) that opens when a pressure higher than a predetermined pressure is applied. The bypass valve (252) may be provided to open when the pressure of one end of the bypass pipe (251) that is connected to the liquid refrigerant flow section (231) is higher than a predetermined pressure.

The liquid refrigerant contained in the liquid refrigerant flow section (231) may absorb heat and expand due to external stimuli, etc. When the liquid refrigerant undergoes thermal expansion, its volume increases, which may damage the refrigerant pipe (20) in the liquid refrigerant flow section (231). This may be defined as a liquid sealing phenomenon.

When the refrigerant flow to the indoor unit (40) is blocked, the bypass valve (252) may be arranged to open to prevent a liquid seal phenomenon in the liquid refrigerant flow section (231). More specifically, when the pressure of the liquid refrigerant flow section (231) is equal to or higher than a predetermined pressure, the bypass valve (252) may be opened. When the bypass valve (252) is opened, a portion of the refrigerant contained in the liquid refrigerant flow section (231) may flow to the low-pressure gas pipe (22). Accordingly, the pressure in the liquid refrigerant flow section (231) may be lowered, thereby preventing a liquid seal phenomenon.

Figure 6 is a schematic diagram illustrating a state in which a refrigerant pipe is blocked when a refrigerant leak occurs in an air conditioner according to one embodiment. Descriptions of contents that overlap with the above contents are omitted below.

Even if the control valve (242) and the low-pressure pipe valve (222) are closed, there may be cases where the refrigerant flows toward the indoor unit (40) in the low-pressure gas pipe (22) and the pressure regulating pipe (241). The low-pressure gas pipe (22) may include a check valve (51). The check valve (51) may be arranged upstream of one end of the pressure regulating pipe (241) with respect to the flow direction of the refrigerant in the low-pressure gas pipe (22). Therefore, the refrigerant in the pressure regulating pipe (241) and the low-pressure gas pipe (22) may be prevented from flowing toward the indoor unit (40). That is, the check valve (51) may be provided to block the refrigerant in the low-pressure gas pipe (22) from flowing toward the indoor unit (40).

Fig. 7 is a drawing schematically illustrating the structure of a multi-air conditioner according to one embodiment. In the following, descriptions of contents overlapping with the above contents are omitted.

Referring to Fig. 7, the multi-air conditioner (3) may be a simultaneous cooling and heating multi-air conditioner (3).

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

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 (40A, 40B, 40C, 40D, 40E, 40F) is illustrated as six in the figure, the number of indoor units (40) is not limited thereto and may be provided in various ways.

The 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.

The indoor unit (40) may include an indoor blower fan (41). The indoor blower fan (41) 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 where refrigeration is required after heat exchange of the refrigerant occurs in the indoor heat exchanger (42).

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 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 be branched 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).

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 (40) to the outdoor unit (10). The low-pressure gas pipe (22) may be branched to connect a plurality of indoor units (40A, 40B, 40C, 40D, 40E, 40F) and the outdoor unit (10).

The refrigerant pipe (20) may include a liquid pipe (23). The liquid pipe (23) may be arranged 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 arranged 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).

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

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).

The multi-air conditioner (3) may include a heating/cooling switch (30). The heating/cooling switch (30) may include a part of a refrigerant pipe (20). The heating/cooling switch (30) may perform a room heating operation in which all indoor units (40A, 40B, 40C, 40D, 40E, 40F) are heated, a room cooling operation in which all indoor units (40A, 40B, 40C, 40D, 40E, 40F) are cooled, a heating main operation in which a small number of indoor units are cooled and the remaining large number of indoor units are heated, and a cooling main operation in which a small number of indoor units are heated and the remaining large number of indoor units are cooled.

That is, the air conditioning switch (30) may include a control unit. The control unit 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 all-room heating operation, all-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. A detailed description of the control unit controlling the refrigerant pipe (20) will be described later.

FIG. 8 is an enlarged view showing a part of a heating/cooling switch and an indoor unit of a multi-air conditioner according to one embodiment. FIG. 9 is a schematic drawing showing a state in which a refrigerant pipe connected to a first indoor unit in FIG. 8 is blocked, and a state in which refrigerant flows in a pressure regulating pipe connected to a second indoor unit when the second indoor unit is switched from heating mode to cooling mode. FIG. 10 is a schematic drawing showing a state in which refrigerant flows in a bypass pipe connected to the first indoor unit in FIG. 9, and a state in which the second indoor unit is switched to cooling mode and operates.

Below, the operation of the multi-air conditioner (3) is explained by explaining the operation of the first indoor unit (40A) and the second indoor unit (40B) separately. Descriptions of contents that overlap with the above contents are omitted below.

Referring to FIGS. 8 to 10, the refrigerant pipe (20) may include a high-pressure pipe valve (212). The high-pressure pipe valve (212) may be provided in the high-pressure gas pipe (21). When the high-pressure pipe valve (212) is closed, the high-pressure gas pipe (21) may be blocked, so that the refrigerant may not flow in the high-pressure gas pipe (21).

The high-pressure gas pipe (21) may include a main high-pressure gas pipe (213) that is provided to supply refrigerant from the outdoor unit (10). The high-pressure gas pipe (21) may include branch high-pressure gas pipes (211A, 211B, 211C, 211D, 211E, 211F) that branch from the high-pressure gas pipe (21) and are respectively connected to a plurality of indoor units (40).

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

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

The refrigerant pipe (20) may include a low-pressure pipe valve (222). The low-pressure pipe valve (222) may be provided in the low-pressure gas pipe (22). When the low-pressure pipe valve (222) is closed, the low-pressure gas pipe (22) is blocked, so that the refrigerant may not flow in the low-pressure gas pipe (22).

The low-pressure gas pipe (22) may include branch low-pressure gas pipes (221A, 221B, 221C, 221D, 221E, 221F) that are each connected to a plurality of indoor units (40A, 40B, 40C, 40D, 40E, 40F). The low-pressure gas pipe (22) may include a main low-pressure gas pipe (224) that is connected to the branch low-pressure gas pipes (221A, 221B, 221C, 221D, 221F, 221E) so that refrigerant is recovered to the outdoor unit (10).

The first indoor unit (40A) may be connected to the first branch low-pressure gas pipe (221A). The first branch low-pressure gas pipe (221A) may be provided with a first low-pressure pipe valve (222A). The refrigerant pipe (20) may include a first gas pipe connection pipe (261A) connected to the first indoor unit (40A). The first branch low-pressure gas pipe (221A) may be combined with the first gas pipe connection pipe (261A).

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

The refrigerant pipe (20) 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 the refrigerant may not flow in the liquid pipe (23).

The liquid pipe (23) may include branched liquid pipes (234A, 234B, 234C, 234D, 234E, 234F) that are branched and connected to each indoor unit (40).

The first indoor unit (40A) can be connected to the first branch liquid pipe (234A). The first branch liquid pipe (234A) can be provided with a first liquid pipe valve (222A).

The second indoor unit (40B) can be connected to the second branch liquid pipe (234B). The second branch liquid pipe (234B) can be provided with a second liquid pipe valve (222B).

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

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

The first indoor unit (40A) can be connected to the first liquid pipe connection pipe (43A). The first liquid pipe connection pipe (43A) can be provided with a first liquid pipe connection pipe valve (44A).

The second indoor unit (40B) can be connected to the second liquid pipe connection pipe (43B). The second liquid pipe connection pipe (43B) can be provided with a second liquid pipe connection pipe valve (44B).

The refrigerant pipe (20) may include a control valve (242). The control valve (242) may be provided in the pressure regulating pipe (241).

A first control valve (242A) may be provided in the first pressure control pipe (241A). A second control valve (242B) may be provided in the second pressure control pipe (241B).

The air conditioner (30) may include a control unit. The control unit may control the flow of refrigerant in the refrigerant pipe (20) by controlling the opening and closing of the high pressure pipe valve (212), the low pressure pipe valve (222), the liquid pipe valve (232), and the regulating valve (242).

The control unit may be provided to control the opening and closing of the refrigerant pipe connected to the first indoor unit (40A) and the refrigerant pipe connected to the second indoor unit (40), so that the first indoor unit (40A) and the second indoor unit (40B) can operate independently. More specifically, the control unit may close the first high-pressure pipe valve (212A) and open the first low-pressure pipe valve (222A) and the first liquid pipe valve (232A) so that the first indoor unit (40A) performs a cooling operation. In addition, the control unit may control the closing of the second low-pressure pipe valve (222B) and the opening of the second high-pressure pipe valve (212B) and the second liquid pipe valve (232B) so that the second indoor unit (40B) performs a heating operation.

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. 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 by including the above-described structure.

Below, we will examine in detail the case where refrigerant leakage occurs in the refrigerant pipe (20) connected to the first indoor unit (40A).

In the event of a refrigerant leak in the refrigerant pipe (20) connected to the first indoor unit (40A), the multi-air conditioner (3) may be arranged to block the refrigerant flow to the first indoor unit (40A). More specifically, in the event of a refrigerant leak, the control unit may close the first high-pressure pipe valve (212A), the first low-pressure pipe valve (222A), the first liquid pipe valve (232A), and the first liquid pipe connection valve (232A). As a result, the refrigerant flow in the first indoor unit (40) may be blocked.

The first pressure regulating pipe (241A) may include a first check valve (243A) provided in the first pressure regulating pipe (241A). The first check valve (243A) may be positioned upstream of the first regulating valve (242A) with respect to the flow direction of the refrigerant in the first pressure regulating pipe (241A). That is, the first check valve (243A) may be provided to block the refrigerant from flowing in the direction toward the first indoor unit (40A).

The first branch low-pressure gas pipe (221A) may include a second check valve (223A) provided in the first branch low-pressure gas pipe (221A). The second check valve (223A) may be positioned upstream of the first low-pressure pipe valve (222A) with respect to the flow direction of the refrigerant in the first branch low-pressure gas pipe (221A). That is, the second check valve (223A) may be provided to block the refrigerant from flowing in the direction toward the first indoor unit (40A).

The first branch liquid pipe (234A) may include a first liquid refrigerant flow section (231A) defined as a section between the first liquid pipe valve (232A) and the first liquid pipe connecting valve (44A). When the flow of refrigerant to the first indoor unit (40A) is blocked, the first liquid refrigerant flow section (231A) may be closed. The first liquid refrigerant flow section (231A) may contain refrigerant in a liquid state.

The refrigerant pipe (20) may include a first bypass pipe (251A) provided on the first indoor unit (40A) side. The first bypass pipe (251A) may connect the first branch low-pressure gas pipe (221A) and the first branch liquid pipe (234A). More specifically, one end of the first bypass pipe (251A) may be joined to the first liquid refrigerant flow section (231A). The other end of the first bypass pipe (251A) may be formed to be joined to the first branch low-pressure gas pipe (221A). The other end of the first bypass pipe (251A) may be arranged downstream of the first low-pressure pipe valve (222A) with respect to the flow direction of the refrigerant in the first branch low-pressure gas pipe (221A).

The refrigerant pipe (20) may include a first bypass valve (252A) provided on the first indoor unit (40A) side. The first bypass valve (252A) may be provided in the first bypass pipe (251A). The first bypass valve (252A) may be a pressure regulating valve (242A) that opens when a pressure higher than a predetermined pressure is applied. The first bypass valve (252A) may be provided to open when the pressure of one end of the first bypass pipe (251A) that is combined with the first liquid refrigerant flow section (231A) is higher than a predetermined pressure.

The liquid refrigerant contained in the first liquid refrigerant flow section (231A) may absorb heat and expand due to external stimuli, etc. When the liquid refrigerant undergoes thermal expansion, its volume increases, which may damage the refrigerant pipe (20) in the first liquid refrigerant flow section (231A). This may be defined as a liquid sealing phenomenon.

When the refrigerant flow to the first indoor unit (40A) is blocked, the first bypass valve (252A) may be arranged to open to prevent a liquid seal phenomenon in the first liquid refrigerant flow section (231A). More specifically, when the pressure of the first liquid refrigerant flow section (231A) is equal to or higher than a predetermined pressure, the first bypass valve (252A) may be opened. When the first bypass valve (252A) is opened, a portion of the refrigerant contained in the first liquid refrigerant flow section (231A) may flow to the first branch low-pressure gas pipe (221A). Therefore, the pressure in the first liquid refrigerant flow section (231A) may be lowered, thereby preventing a liquid seal phenomenon.

The structure for preventing liquid sealing in the first indoor unit (40A) described above can be applied equally to the second indoor unit (40B) to the sixth indoor unit (40F) of Fig. 7. The control unit can prevent refrigerant leakage and liquid sealing phenomenon by controlling the opening and closing of the refrigerant pipe (20) connected to the indoor unit (40) where refrigerant leakage has occurred.

Hereinafter, the process of switching between cooling and heating modes of the second indoor unit (40B) will be described in detail. The second indoor unit (40B) can operate in heating mode. More specifically, the second branch high-pressure gas pipe (211B) and the second branch liquid pipe (234B) may be open, and the second branch low-pressure gas pipe (221B) may be closed. When the second indoor unit (40B) switches from heating mode to cooling mode, the second branch high-pressure gas pipe (211B) may be closed, and the second control valve (242B) provided in the second pressure control pipe (241B) may be opened. As a result, the pressure difference between both sides of the second branch low-pressure gas pipe (221B) with respect to the second low-pressure pipe valve (222B) may be reduced. Thereafter, the second low-pressure pipe valve (222B) may be closed, and the second branch low-pressure gas pipe (221B) may be opened. The refrigerant can be introduced into the second indoor unit (40B) through the second branch liquid pipe (234B). The refrigerant introduced into the second indoor unit (40B) can flow to the outdoor unit (10) through the second branch low-pressure gas pipe (221B).

The cooling/heating mode switching process in the above-mentioned second indoor unit (40B) can be applied equally to the first indoor unit (40A), the third indoor unit (40C) to the sixth indoor unit (40F) of Fig. 7. The control unit can switch between cooling/heating modes by controlling the refrigerant pipe (20) connected to the indoor unit (40) that requires cooling/heating mode switching.

In addition, the control unit may be provided to control the opening and closing of the high-pressure pipe valve (212), the low-pressure pipe valve (222), and the liquid pipe valve (232) to stop the operation of the indoor unit (40) that requires operation stop.

Fig. 11 is an enlarged view showing a part of the cooling/heating switch and the indoor unit of a multi-air conditioner according to one embodiment. The following description assumes that a refrigerant leak has occurred in the first indoor unit (40A). Descriptions of contents that overlap with the above contents are omitted below.

Even if the first control valve (242A) and the first low-pressure pipe valve (222A) connected to the first indoor unit (40A) are closed, there may be cases where the refrigerant flows toward the first indoor unit (40A) in the first branch low-pressure gas pipe (221A) and the first pressure regulating pipe (241A). The first branch low-pressure gas pipe (221A) may include a check valve (51A). The check valve (51A) may be arranged upstream of one end of the first pressure regulating pipe (241A) with respect to the flow direction of the refrigerant in the first branch low-pressure gas pipe (221A). Therefore, the refrigerant in the first pressure regulating pipe (241A) and the first branch low-pressure gas pipe (221A) can be prevented from flowing toward the first indoor unit (40A). That is, the check valve (51A) can be provided to block the refrigerant in the first branch low-pressure gas pipe (221A) from flowing toward the first indoor unit (40A).

The structure including the check valve (51) that prevents the flow of refrigerant to the first indoor unit (40A) by the check valve (51A) described above can be equally applied to the second indoor unit (40B) to the sixth indoor unit (40F) of FIG. 7.

An air conditioner (1) according to one embodiment includes an outdoor unit (10). The air conditioner (1) includes an indoor unit (40) connected to the outdoor unit (10). The air conditioner (1) includes a refrigerant pipe (20) provided to connect the outdoor unit (10) and the indoor unit (40) and to allow refrigerant to flow. The refrigerant pipe (20) includes a high-pressure gas pipe (21) provided to supply refrigerant to the indoor unit (40). The refrigerant pipe (20) includes a high-pressure pipe valve (212) provided in the high-pressure gas pipe (21). The refrigerant pipe (20) includes a low-pressure gas pipe (22) provided to recover refrigerant to the outdoor unit (10). The refrigerant pipe (20) includes a low-pressure pipe valve (222) provided in the low-pressure gas pipe (22). The above refrigerant pipe (20) includes a liquid pipe (23). The above refrigerant pipe (20) includes a liquid pipe valve (232) provided in the liquid pipe (23). The above refrigerant pipe (20) includes a liquid pipe connection pipe (43) that is joined to the liquid pipe (23) and connected to the indoor unit (40). The above refrigerant pipe (20) includes a liquid pipe connection pipe valve (44) provided in the liquid pipe connection pipe (43). The above refrigerant pipe (20) includes a bypass pipe (251) that connects the low-pressure gas pipe (22) and the liquid pipe (23). The above refrigerant pipe (20) includes a bypass valve (252) provided in the bypass pipe (251). The above liquid pipe (23) includes a liquid refrigerant flow section (231) defined as a section between the liquid pipe valve (232) and the liquid pipe connection pipe valve (44). The above bypass pipe (251) is provided so that one end is connected to the liquid refrigerant flow section (231) and the other end is connected to the low-pressure gas pipe (22).

When the refrigerant leaks from the indoor unit (40), the high-pressure pipe valve (212), the low-pressure pipe valve (222), the liquid pipe valve (232), and the liquid pipe connection valve (44) can be closed to block the refrigerant flow to the indoor unit (40). When the refrigerant flow to the indoor unit (40) is blocked, the bypass valve (252) can be opened when the pressure of the liquid refrigerant flow section (231) is equal to or higher than a predetermined pressure to prevent a liquid seal phenomenon in the liquid refrigerant flow section (231), so that a portion of the refrigerant contained in the liquid refrigerant flow section (231) can flow to the low-pressure gas pipe (22).

The other end of the above bypass pipe (251) may be placed downstream of the low-pressure pipe valve (222) with respect to the flow direction of the refrigerant in the low-pressure gas pipe (22).

The above refrigerant pipe (20) may further include a pressure regulating pipe (241) connected to the low-pressure gas pipe (22) and a regulating valve (242) provided in the pressure regulating pipe (241). One end of the pressure regulating pipe (241) may be connected upstream of the low-pressure pipe valve (222) with respect to the flow direction of the refrigerant in the low-pressure gas pipe (22). The other end of the pressure regulating pipe (241) may be connected downstream of the low-pressure pipe valve (222) with respect to the flow direction of the refrigerant in the low-pressure gas pipe (22). The regulating valve (242) may be opened to allow the refrigerant to flow from one end of the pressure regulating pipe (241) to the other end of the pressure regulating pipe (241) to reduce the pressure difference between both sides of the low-pressure gas pipe (22) with respect to the low-pressure pipe valve (222).

The above pressure regulating pipe (241) may include a first check valve (243) positioned upstream of the regulating valve (242) with respect to the flow direction of the refrigerant in the pressure regulating pipe (241). The low-pressure gas pipe (22) may include a second check valve (223) positioned upstream of the low-pressure pipe valve (222) with respect to the flow direction of the refrigerant in the low-pressure gas pipe (22).

The first check valve (243) may be provided to block the refrigerant of the pressure regulating pipe (241) from flowing from the other end of the pressure regulating pipe (241) to one end of the pressure regulating pipe (241). The second check valve (223) may be provided to block the refrigerant of the low-pressure gas pipe (22) from flowing toward the indoor unit (40).

The above low-pressure gas pipe (22) may include a check valve (51) positioned upstream of one end of the pressure regulating pipe (241) with respect to the flow direction of the refrigerant in the above low-pressure gas pipe (22).

The above check valve (51) may be provided to block the refrigerant in the low-pressure gas pipe (22) from flowing toward the indoor unit (40).

The above refrigerant pipe (20) may further include a gas pipe connecting pipe (261) that connects the high-pressure gas pipe (21) and 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) and the low-pressure gas pipe (22). The other end of the gas pipe connecting pipe (261) may be connected to the indoor unit (40).

The device may further include a control unit that controls the opening and closing of the high-pressure pipe valve (212), the low-pressure pipe valve (222), the liquid pipe valve (232), the liquid pipe connection pipe valve (44), and the control valve (242) to control the flow of refrigerant in the refrigerant pipe (20).

The above control unit can control to close the high pressure pipe valve (212) so that the air conditioner (1) operates in cooling mode. The above control unit can control to open the low pressure pipe valve (222) and the liquid pipe valve (232) so that the air conditioner (1) operates in cooling mode.

The above control unit can control to close the low pressure pipe valve (222) so that the air conditioner (1) operates in heating mode. The above control unit can control to open the high pressure pipe valve (212) and the liquid pipe valve (232) so that the air conditioner (1) operates in heating mode.

A multi-air conditioner (3) according to one embodiment includes an outdoor unit (10). The multi-air conditioner (3) includes an indoor unit (40) connected to the outdoor unit (10). The indoor unit (40) includes a first indoor unit (40A). The indoor unit (40) includes a second indoor unit (40B) spaced apart from the first indoor unit (40). The multi-air conditioner (3) includes a heating and cooling switch (30) including a portion of a refrigerant pipe (20) provided to connect the outdoor unit (10) and the indoor unit (40) and to allow refrigerant to flow. The refrigerant pipe (20) includes a high-pressure gas pipe (21) provided to supply refrigerant to the indoor unit (40). The refrigerant pipe (20) includes a high-pressure pipe valve (212) provided in the high-pressure gas pipe (21). The above refrigerant pipe (20) includes a low-pressure gas pipe (22) provided so that the refrigerant is recovered to the outdoor unit (10). The internal pipe includes a low-pressure pipe valve (222) provided in the low-pressure gas pipe (22). The refrigerant pipe (20) includes a liquid pipe (23). The refrigerant pipe (20) includes a liquid pipe valve (232) provided in the liquid pipe (23). The refrigerant pipe (20) includes a liquid pipe connection pipe (43) that is connected to the indoor unit (40) by being joined to the liquid pipe (23). The refrigerant pipe (20) includes a liquid pipe connection pipe valve (44) provided in the liquid pipe connection pipe (43). The refrigerant pipe (20) includes a bypass pipe (251) that connects the low-pressure gas pipe (22) and the liquid pipe (23). The above refrigerant pipe (20) includes a bypass valve (252) provided in the bypass pipe (251). The above liquid pipe (23) includes a liquid refrigerant flow section (231) defined as a section between the liquid pipe valve (232) and the liquid pipe connection valve (44). The above bypass pipe (251) is provided so that one end is connected to the liquid refrigerant flow section (231). The above bypass pipe (251) is provided so that the other end is connected to the low-pressure gas pipe (22). The above-described heating and cooling switch (30) includes a control unit that controls the closing of the high-pressure pipe valve (212A), the low-pressure pipe valve (222A), and the liquid pipe valve (232A) so as to block the high-pressure gas pipe (21A), the low-pressure gas pipe (22A), and the liquid pipe (23A) connected to the first indoor unit (40A) when the operation of the first indoor unit (40A) is stopped.

When the refrigerant leaks from the first indoor unit (40A), the control unit can control the high-pressure pipe valve (212A), the low-pressure pipe valve (222A), the liquid pipe valve (232A), and the liquid pipe connection valve (44A) connected to the first indoor unit (40A) to close so as to block the flow of refrigerant to the first indoor unit (40A). When the flow of refrigerant to the first indoor unit (40A) is blocked, the bypass valve (252A) can be provided to open when the pressure in the liquid refrigerant flow section (231) is equal to or higher than a predetermined pressure so as to prevent a liquid seal phenomenon in the liquid refrigerant flow section (231A), so that a portion of the refrigerant contained in the liquid refrigerant flow section (231A) can flow to the low-pressure gas pipe (22A).

The other end of the above bypass pipe (251A) may be placed downstream of the low-pressure pipe valve (222A) with respect to the flow direction of the refrigerant in the low-pressure gas pipe (22A).

The above-described heating and cooling switch (30) may include a pressure regulating pipe (241A) that is connected to the low-pressure gas pipe (22A). The above-described heating and cooling switch (30) may further include a regulating valve (242A) that is provided in the pressure regulating pipe (241A). One end of the pressure regulating pipe (241A) may be connected upstream of the low-pressure pipe valve (222A) with respect to the flow direction of the refrigerant in the low-pressure gas pipe (22A). The other end of the pressure regulating pipe (241A) may be connected downstream of the low-pressure pipe valve (222A) with respect to the flow direction of the refrigerant in the low-pressure gas pipe (22A). The above control unit can open the control valve (242A) to allow the refrigerant to flow from one end of the pressure control pipe (241A) to the other end of the pressure control pipe (241A) to reduce the pressure difference between both sides of the low-pressure gas pipe (22A) with respect to the low-pressure pipe valve (222A).

The pressure regulating pipe (241A) may include a first check valve (243A) positioned upstream of the regulating valve (242A) with respect to the flow direction of the refrigerant in the pressure regulating pipe (241A). The low-pressure gas pipe (22A) may include a second check valve (223A) positioned upstream of the low-pressure pipe valve (222A) with respect to the flow direction of the refrigerant in the low-pressure gas pipe (22A). The first check valve (243A) may be provided to block the refrigerant in the pressure regulating pipe (241A) from flowing from the other end of the pressure regulating pipe (241A) to one end of the pressure regulating pipe (241A). The second check valve (223A) may be provided to block the refrigerant in the low-pressure gas pipe (22A) from flowing toward the indoor unit (40A).

The above low-pressure gas pipe (22A) may further include a check valve (51A) positioned upstream of one end of the pressure regulating pipe (241A) with respect to the flow direction of the refrigerant in the above low-pressure gas pipe (22A). The check valve (51A) may be provided to block the refrigerant in the above low-pressure gas pipe (22A) from flowing toward the indoor unit (40A).

The above refrigerant pipe (20) may further include a gas pipe connection pipe (261) that connects the high-pressure gas pipe (21) and the low-pressure gas pipe (22) to the indoor unit (40). The high-pressure gas pipe (21) may include a main high-pressure gas pipe (213) that is provided to supply refrigerant from the outdoor unit (10). The high-pressure gas pipe (21) may include branch high-pressure gas pipes (211A, 211B, 211C, 211D, 211E, 211F) that branch from the main high-pressure gas pipe (213) and merge with the gas pipe connection pipe (261).

The above refrigerant pipe (20) may further include a gas pipe connection pipe (261) that connects the high-pressure gas pipe (21) and the low-pressure gas pipe (22) to the indoor unit (40). The low-pressure gas pipe (22) may include a branch low-pressure gas pipe (221A, 221B, 221C, 221D, 221E, 221F) that is joined to the gas pipe connection pipe (261). The low-pressure gas pipe (22) may include a main low-pressure gas pipe (224) that is connected to the branch low-pressure gas pipe (221A, 221B, 221C, 221D, 221E, 221F) so that the refrigerant is recovered to the outdoor unit (10).

According to the idea of the present disclosure, when the flow of refrigerant is blocked to prevent refrigerant leakage, the refrigerant contained in the liquid refrigerant flow section can be prevented from forming a liquid seal in the liquid pipe by flowing it into the low-pressure gas pipe.

According to the idea of the present disclosure, by installing a check valve in a refrigerant pipe connected to a high-pressure gas pipe and a low-pressure gas pipe, the flow of refrigerant toward the indoor unit side can be prevented, thereby reducing refrigerant leakage from the indoor unit side.

The effects obtainable from the present disclosure are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by a person skilled in the art to which the present disclosure belongs from the description below.

The above has been illustrated and described with respect to specific embodiments. However, it is not limited to the above embodiments, and those skilled in the art to which the invention pertains can make various modifications and implementations without departing from the gist of the technical idea of the invention described in the claims below.

1, 2: Air conditioner
10: Outdoor unit
11A, 11B: Compressor
13: 4 way valve
4: High pressure branch pipe
15: Outdoor heat exchanger
16: Outdoor blower fan
20: Refrigerant pipe
21: High pressure gas pipe
212: High pressure valve
22: Low pressure gas pipe
222: Low pressure line valve
23: Liquid pipe
231: Liquid refrigerant flow section
232: Liquid pipe valve
241: Pressure regulating tube
242: Control valve
251: Bypass pipe
252: Bypass valve
261: Gas pipe connector
3, 4: Multi-air conditioner
30: Air conditioning switch
40: Indoor unit
43: Liquid pipe connector
44: Liquid pipe connection valve

Claims (20)

Outdoor unit (10);
An indoor unit (40) connected to the outdoor unit (10); and
It includes a refrigerant pipe (20) that is provided to connect the outdoor unit (10) and the indoor unit (40) to allow the refrigerant to flow;
The above refrigerant pipe (20) is
A high-pressure gas pipe (21) provided to supply refrigerant to the above indoor unit (40) and a high-pressure pipe valve (212) provided in the above-mentioned high-pressure gas pipe (21);
A low-pressure gas pipe (22) provided to recover refrigerant to the outdoor unit (10) and a low-pressure pipe valve (222) provided in the low-pressure gas pipe (22),
A liquid pipe (23) and a liquid pipe valve (232) provided in the liquid pipe (23),
A liquid pipe connection pipe (43) that is connected to the indoor unit (40) by being combined with the liquid pipe (23) and a liquid pipe connection valve (44) provided in the liquid pipe connection pipe (43).
It includes a bypass pipe (251) connecting the above low-pressure gas pipe (22) and the above liquid pipe (23) and a bypass valve (252) provided in the above bypass pipe (251).
The above liquid pipe (23) includes a liquid refrigerant flow section (231) defined as a section between the liquid pipe valve (232) and the liquid pipe connection valve (44).
The above bypass pipe (251) is provided in an air conditioner (1) in which one end is connected to the liquid refrigerant flow section (231) and the other end is connected to the low-pressure gas pipe (22). In the first paragraph,
When the refrigerant leaks from the above refrigerant pipe (20), the high pressure pipe valve (212), the low pressure pipe valve (222), the liquid pipe valve (232) and the liquid pipe connection valve (44) are closed to block the flow of refrigerant to the indoor unit (40).
An air conditioner (1) in which, when the flow of refrigerant to the indoor unit (40) is blocked, the bypass valve (252) is opened when the pressure of the liquid refrigerant flow section (231) is higher than a predetermined pressure to prevent a liquid seal phenomenon in the liquid refrigerant flow section (231), thereby allowing some of the refrigerant contained in the liquid refrigerant flow section (231) to flow into the low-pressure gas pipe (22). In the first paragraph,
An air conditioner (1) in which the other end of the above bypass pipe (251) is positioned downstream of the low-pressure pipe valve (222) with respect to the flow direction of the refrigerant in the above low-pressure gas pipe (22). In the second paragraph,
The above refrigerant pipe (20) further includes a pressure regulating pipe (241) that is connected to the low-pressure gas pipe (22) and a regulating valve (242) provided in the pressure regulating pipe (241).
One end of the above pressure regulating pipe (241) is connected upstream of the low pressure pipe valve (222) with respect to the flow direction of the refrigerant in the low pressure gas pipe (22).
The other end of the above pressure regulating pipe (241) is connected downstream from the low pressure pipe valve (222) with respect to the flow direction of the refrigerant in the low pressure gas pipe (22).
The above-mentioned control valve (242) is an air conditioner (1) that opens to allow refrigerant to flow from one end of the pressure control pipe (241) to the other end of the pressure control pipe (241) to reduce the pressure difference between both sides of the low-pressure gas pipe (22) based on the low-pressure pipe valve (222). In paragraph 4,
The above pressure regulating pipe (241) includes a first check valve (243) positioned upstream of the regulating valve (242) with respect to the flow direction of the refrigerant in the above pressure regulating pipe (241).
An air conditioner (1) in which the low-pressure gas pipe (22) includes a second check valve (223) positioned upstream of the low-pressure pipe valve (222) with respect to the flow direction of the refrigerant in the low-pressure gas pipe (22). In paragraph 5,
The above first check valve (243) is provided to block the refrigerant of the pressure regulating pipe (241) from flowing from the other end of the pressure regulating pipe (241) to one end of the pressure regulating pipe (241).
The above second check valve (223) is provided in an air conditioner (1) to block the refrigerant in the low-pressure gas pipe (22) from flowing toward the indoor unit (40). In paragraph 4,
The above low-pressure gas pipe (22) is an air conditioner (2) including a check valve (50) positioned upstream of one end of the pressure regulating pipe (241) with respect to the flow direction of the refrigerant in the above low-pressure gas pipe (22). In Article 7,
The above check valve (50) is provided in an air conditioner (2) to block the refrigerant in the low-pressure gas pipe (22) from flowing toward the indoor unit (40). In the first paragraph,
The above refrigerant pipe (20) further includes a gas pipe connection pipe (261) that connects the high-pressure gas pipe (21) and the low-pressure gas pipe (22) to the indoor unit (40).
One end of the above gas pipe connecting pipe (261) is connected to the high pressure gas pipe (21) and the low pressure gas pipe (22).
The other end of the above gas pipe connecting pipe (261) is connected to the air conditioner (1) and the indoor unit (40). In paragraph 4,
An air conditioner (1) further comprising a control unit that controls the opening and closing of the high-pressure pipe valve (212), the low-pressure pipe valve (222), the liquid pipe valve (232), the liquid pipe connection valve (44), and the control valve (242) to control the flow of refrigerant in the refrigerant pipe (20). In Article 10,
The above control unit controls the air conditioner (1) to close the high pressure pipe valve (212) and open the low pressure pipe valve (222) and the liquid pipe valve (232) so that the air conditioner (1) operates in cooling mode. In Article 10,
The above control unit controls the air conditioner (1) to close the low pressure pipe valve (222) and open the high pressure pipe valve (212) and the liquid pipe valve (232) so that the air conditioner (1) operates in heating mode. Outdoor unit (10);
An indoor unit (40) connected to the outdoor unit (10), comprising a first indoor unit (40A) and a second indoor unit (40B) spaced apart from the first indoor unit (40A); and
It includes a heating and cooling switch (30) including a part of a refrigerant pipe (20) that is provided to connect the outdoor unit (10) and the indoor unit (40) to allow refrigerant to flow,
The above refrigerant pipe (20) is
A high-pressure gas pipe (21) provided to supply refrigerant to the above indoor unit (40) and a high-pressure pipe valve (212) provided in the above-mentioned high-pressure gas pipe (21);
A low-pressure gas pipe (22) provided to recover refrigerant to the outdoor unit (10) and a low-pressure pipe valve (222) provided in the low-pressure gas pipe (22),
A liquid pipe (23) and a liquid pipe valve (232) provided in the liquid pipe (23),
A liquid pipe connection pipe (43) that is connected to the indoor unit (40) by being combined with the liquid pipe (23) and a liquid pipe connection valve (44) provided in the liquid pipe connection pipe (43).
It includes a bypass pipe (251) connecting the above low-pressure gas pipe (22) and the above liquid pipe (23) and a bypass valve (252) provided in the above bypass pipe (251).
The above liquid pipe (23) includes a liquid refrigerant flow section (231) defined as a section between the liquid pipe valve (232) and the liquid pipe connection valve (44).
The above bypass pipe (251) is provided so that one end is connected to the liquid refrigerant flow section (231) and the other end is connected to the low-pressure gas pipe (22).
The above-mentioned heating and cooling switch (30) is a multi-air conditioner (3) including a control unit that controls the closing of the high-pressure pipe valve (212A), the low-pressure pipe valve (222A), and the liquid pipe valve (232A) so as to block the high-pressure gas pipe (21A), the low-pressure gas pipe (22A), and the liquid pipe (23A) connected to the first indoor unit (40A) when the operation of the first indoor unit (40A) is stopped. In Article 13,
When the refrigerant leaks from the above refrigerant pipe (20), the control unit controls the high pressure pipe valve (212A), the low pressure pipe valve (222A), the liquid pipe valve (232A) and the liquid pipe connection valve (44A) connected to the first indoor unit (40A) to close so as to block the flow of refrigerant to the first indoor unit (40A).
A multi-air conditioner (3) in which, when the refrigerant flow to the first indoor unit (40A) is blocked, the bypass valve (252A) is opened when the pressure in the liquid refrigerant flow section (231A) is higher than a predetermined pressure to prevent a liquid seal phenomenon in the liquid refrigerant flow section (231A), thereby allowing some of the refrigerant contained in the liquid refrigerant flow section (231A) to flow to the low-pressure gas pipe (22A). In Article 13,
A multi-air conditioner (3) in which the other end of the above bypass pipe (251A) is positioned downstream of the low-pressure pipe valve (222A) with respect to the flow direction of the refrigerant in the above low-pressure gas pipe (22A). In Article 14,
The above-mentioned heating and cooling switch (30) further includes a pressure regulating pipe (241A) connected to the low-pressure gas pipe (22A) and a regulating valve (242A) provided in the pressure regulating pipe (241A).
One end of the above pressure regulating pipe (241A) is connected upstream of the low pressure pipe valve (222A) with respect to the flow direction of the refrigerant in the low pressure gas pipe (22A).
The other end of the above pressure regulating pipe (241A) is connected downstream from the low pressure pipe valve (222A) with respect to the flow direction of the refrigerant in the low pressure gas pipe (22A).
The above control unit is a multi-air conditioner (3) that opens the control valve (242A) to reduce the pressure difference between both sides of the low-pressure gas pipe (22A) based on the low-pressure pipe valve (222A) by flowing the refrigerant from one end of the pressure control pipe (241A) to the other end of the pressure control pipe (241A). In Article 16,
The above pressure regulating pipe (241A) includes a first check valve (243A) positioned upstream of the regulating valve (242A) with respect to the flow direction of the refrigerant in the above pressure regulating pipe (241A).
The above low-pressure gas pipe (22A) includes a second check valve (223A) positioned upstream of the low-pressure pipe valve (222A) with respect to the flow direction of the refrigerant in the above low-pressure gas pipe (22).
The above first check valve (243A) is provided to block the refrigerant of the pressure regulating pipe (241) from flowing from the other end of the pressure regulating pipe (241) to one end of the pressure regulating pipe (241).
The above second check valve (223A) is provided in a multi-air conditioner (3) to block the refrigerant in the low-pressure gas pipe (22A) from flowing toward the indoor unit (40A). In Article 16,
The above low-pressure gas pipe (22A) further includes a check valve (51A) positioned upstream of one end of the pressure regulating pipe (241A) with respect to the flow direction of the refrigerant in the above low-pressure gas pipe (22A).
The above check valve (51A) is provided in a multi-air conditioner (4) to block the refrigerant in the low-pressure gas pipe (22A) from flowing toward the indoor unit (40A). In Article 13,
The above refrigerant pipe (20) further includes a gas pipe connection pipe (261) that connects the high-pressure gas pipe (21) and the low-pressure gas pipe (22) to the indoor unit (40).
The above high pressure gas pipe (21) is
A main high-pressure gas pipe (213) provided to supply refrigerant from the outdoor unit (10) and
A multi-air conditioner (3) including branch high-pressure gas pipes (211A, 211B, 211C, 211D, 211E, 211F) branched from the above main high-pressure gas pipe (213) and connected to the above gas pipe connecting pipe (261). In Article 13,
The above refrigerant pipe (20) further includes a gas pipe connection pipe (261) that connects the high-pressure gas pipe (21) and the low-pressure gas pipe (22) to the indoor unit (40).
The above low pressure gas pipe (22) is
Branch low-pressure gas pipes (221A, 221B, 221C, 221D, 221E, 221F) that are connected to the above gas pipe connecting pipe (261) and
A multi-air conditioner (3) including a main low-pressure gas pipe (224) connected to the above branch low-pressure gas pipes (221A, 221B, 221C, 221D, 221E, 221F) so that refrigerant is recovered to the outdoor unit (10).

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