Air conditioner including heat exchanger

Abstract

The disclosed air conditioner includes a heat exchanger. The heat exchanger comprises: multiple heat exchange units each having multiple heat transfer tubes through which a refrigerant flows; and multiple connection units connecting the multiple heat exchange units in series to form multiple refrigerant flow paths. At least one of the multiple connection units connects two adjacent heat exchange units so that at least one of the multiple refrigerant flow paths does not join another refrigerant flow path.

Description

Air conditioner with heat exchanger

[0001] The present disclosure relates to an air conditioner having a heat exchanger.

[0002] A heat exchanger may include a plurality of heat transfer tubes arranged vertically in parallel, and upper and lower connection headers connected to one end of the plurality of heat transfer tubes. Refrigerant flowing through the plurality of heat transfer tubes arranged in the lower (first stage) of the plurality of heat transfer tubes flows into the plurality of heat transfer tubes arranged in the upper (second stage) through the upper and lower connection headers. A heat exchanger of this type is disclosed, for example, in Japanese Patent Application Laid-Open No. 2010-112581.

[0003] The upper and lower connection headers of this heat exchanger have a space communicating with a plurality of heat transfer tubes. Refrigerant supplied from a plurality of heat transfer tubes on the upstream side is collected in the space within the upper and lower connection headers and then distributed to a plurality of heat transfer tubes on the downstream side.

[0004] An air conditioner includes an indoor heat exchanger and an outdoor heat exchanger. At least one of the indoor heat exchanger and the outdoor heat exchanger may include a plurality of heat exchangers and a plurality of connecting portions. Each of the plurality of heat exchangers includes a plurality of heat transfer tubes through which a refrigerant flows. The connecting portions connect the plurality of heat exchangers in series to form a plurality of refrigerant passages. Each of the connecting portions connects two adjacent heat exchangers such that the flow directions of the refrigerant flowing in each of the heat exchangers are opposite to each other. At least one of the connecting portions connects two adjacent heat exchangers such that at least one of the plurality of refrigerant passages does not merge with another refrigerant passage.

[0005] FIG. 1 is a schematic perspective view showing the overall configuration of a heat exchanger according to one embodiment of the present disclosure.

[0006] FIG. 2 is a schematic front view of a heat exchanger according to one embodiment of the present disclosure illustrated in FIG. 1.

[0007] FIG. 3 is a drawing showing the first and second rows of a heat exchanger according to one embodiment of the present disclosure illustrated in FIG. 1 separately.

[0008] FIG. 4 is a schematic enlarged view of a connection portion according to one embodiment of the present disclosure.

[0009] FIG. 5 is a drawing showing the first and second rows of a heat exchanger separated according to one embodiment of the present disclosure.

[0010] FIG. 6 is a schematic enlarged view of a connection portion according to one embodiment of the present disclosure.

[0011] Figure 7 is a schematic diagram of one embodiment of an air conditioner according to the present disclosure.

[0012] Figure 8 is a schematic perspective view of a conventional heat exchanger.

[0013] Fig. 9 is a drawing showing the flow of refrigerant in a connection header in a conventional heat exchanger illustrated in Fig. 8.

[0014] FIG. 10 is a schematic perspective view showing the overall configuration of a heat exchanger according to one embodiment of the present disclosure.

[0015] FIG. 11 is a schematic front view and a rear view of a heat exchanger according to one embodiment of the present disclosure illustrated in FIG. 10.

[0016] Figure 12 is a schematic diagram of one embodiment of an air conditioner according to the present disclosure.

[0017] Figure 13a is a diagram showing the flow of refrigerant when the indoor heat exchanger functions as an evaporator.

[0018] Figure 13b is a diagram showing the temperature change of air and refrigerant passing through the second-stage heat exchanger when the indoor heat exchanger functions as an evaporator.

[0019] Figure 14a is a drawing showing the flow of refrigerant in a case where a heat exchanger functions as an evaporator, with the introduction pipe connected to the heat exchanger of the first row (upwind side) and the discharge pipe connected to the heat exchanger of the second row (downwind side).

[0020] Figure 14b is a drawing showing the temperature change of air and refrigerant passing through the heat exchanger when the heat exchanger illustrated in Figure 14a functions as an evaporator.

[0021] Figure 15a is a diagram showing the flow of refrigerant when the indoor heat exchanger functions as a condenser.

[0022] Figure 15b is a drawing showing the temperature change of air and refrigerant passing through the indoor heat exchanger illustrated in Figure 15a when the indoor heat exchanger functions as a condenser.

[0023] It should be understood that the various embodiments and terms used in this document are not intended to limit the technical features described in this document to specific embodiments, but rather to include various modifications, equivalents, or substitutes of the embodiments.

[0024] In connection with the description of the drawings, similar reference numerals may be used for similar or related components.

[0025] The singular form of a noun corresponding to an item may include one or more of said items, unless the relevant context clearly indicates otherwise.

[0026] In this document, each of the phrases "A or B", "at least one of A and B", "at least one of A or B", "A, B, or C", "at least one of A, B, and C", and "at least one of A, B, or C" may include any one of the items listed together in that phrase, or all possible combinations thereof.

[0027] The term "and / or" includes any combination of a plurality of related described elements or any one of a plurality of related described elements.

[0028] Terms such as "first," "second," or "first" or "second" may be used simply to distinguish one component from another and do not qualify the components in any other respect (e.g., importance or order).

[0029] 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.

[0030] The terms "include" or "have" are intended to specify the presence of a feature, number, step, operation, component, part or combination thereof described in this document, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0031] When a component is said to be “connected,” “coupled,” “supported,” or “in contact with” another component, this includes not only cases where the components are directly connected, coupled, supported, or in contact, but also cases where the components are indirectly connected, coupled, supported, or in contact through a third component.

[0032] 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.

[0033] 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.

[0034] In one embodiment, an air conditioner may include a heat pump device to perform a cooling function or a heating function. The heat pump device may include a refrigeration cycle in which a refrigerant circulates along a compressor, a first heat exchanger, an expansion device, and a second heat exchanger. All components of the heat pump device may be housed in a single housing forming the exterior of the air conditioner, such as a window air conditioner or a portable air conditioner. On the other hand, some components of the heat pump device may be housed separately in multiple housings forming a single air conditioner, such as a wall-mounted air conditioner, a standing air conditioner, or a system air conditioner.

[0035] An air conditioner including a plurality of housings may include at least one outdoor unit installed outdoors and at least one indoor unit installed indoors. For example, the air conditioner may be configured such that one outdoor unit and one indoor unit are connected via a refrigerant pipe. For example, the air conditioner may be configured such that one outdoor unit is connected to two or more indoor units via refrigerant pipes. For example, the air conditioner may be configured such that two or more outdoor units and two or more indoor units are connected via a plurality of refrigerant pipes.

[0036] The outdoor unit can be electrically connected to the indoor unit. For example, information (or commands) for controlling the air conditioner can be input through an input interface provided on the outdoor or indoor unit, and the outdoor and indoor units can operate simultaneously or sequentially in response to user input.

[0037] The air conditioner may include an outdoor heat exchanger provided in the outdoor unit, an indoor heat exchanger provided in the indoor unit, and a refrigerant pipe connecting the outdoor heat exchanger and the indoor heat exchanger.

[0038] An outdoor heat exchanger can utilize a phase change (e.g., evaporation or condensation) of the refrigerant to exchange heat between the refrigerant and the outdoor air. For example, while the refrigerant condenses in the outdoor heat exchanger, it releases heat to the outdoor air, and while the refrigerant flowing in the outdoor heat exchanger evaporates, it absorbs heat from the outdoor air.

[0039] Indoor units are installed indoors. For example, indoor units can be categorized into ceiling-mounted, stand-alone, and wall-mounted types depending on their placement. For example, ceiling-mounted indoor units can be categorized into four-way, one-way, and duct-type types depending on how air is discharged.

[0040] Similarly, an indoor heat exchanger can utilize the phase change of the refrigerant (e.g., evaporation or condensation) to exchange heat between the refrigerant and indoor air. For example, while the refrigerant evaporates in the indoor unit, the refrigerant can absorb heat from the indoor air. The cooled indoor air can then be blown through the cooled indoor heat exchanger, thereby cooling the room. Furthermore, while the refrigerant condenses in the indoor heat exchanger, the refrigerant can release heat to the indoor air. By blowing the heated indoor air through the high-temperature indoor heat exchanger, the room can be heated.

[0041] That is, the air conditioner performs a cooling or heating function through a phase change process of the refrigerant circulating between the outdoor heat exchanger and the indoor heat exchanger. To circulate the refrigerant, the air conditioner may include a compressor that compresses the refrigerant. The compressor can suck in refrigerant gas through the suction port and compress the refrigerant gas. The compressor can discharge the high-temperature and high-pressure refrigerant gas through the discharge port. The compressor may be placed inside the outdoor unit.

[0042] The refrigerant may circulate through the refrigerant pipes in the order of a compressor, an outdoor heat exchanger, an expansion device, and an indoor heat exchanger, or in the order of a compressor, an indoor heat exchanger, an expansion device, and an outdoor heat exchanger.

[0043] For example, if an air conditioner has one outdoor unit and one indoor unit directly connected through a refrigerant pipe, the refrigerant may be arranged to circulate between one outdoor unit and one indoor unit through the refrigerant pipe.

[0044] For example, in an air conditioner, if one outdoor unit is connected to two or more indoor units via refrigerant pipes, the refrigerant can flow to multiple indoor units via refrigerant pipes branching from the outdoor unit. The refrigerant discharged from the multiple indoor units can be combined and circulated to the outdoor unit. For example, multiple indoor units can be directly connected in parallel to a single outdoor unit via separate refrigerant pipes.

[0045] Multiple indoor units can operate independently, each according to a user-defined operating mode. That is, some indoor units can operate in cooling mode, while others operate in heating mode. In this case, the refrigerant can be selectively introduced into each indoor unit at either high or low pressure along a designated circulation path via a flow-through valve, described later, and then discharged to the outdoor unit for circulation.

[0046] 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 merge and flow through a single refrigerant pipe, then branch off again at some point and flow into multiple indoor units.

[0047] Multiple outdoor units may all be operated, or at least some may not be operated, depending on the operating load of the multiple indoor units. In this case, the refrigerant may be introduced into the outdoor unit, which is selectively operated, through a flow switching valve and circulated there. The air conditioner may include an expansion device to reduce the pressure of the refrigerant flowing into the heat exchanger. For example, the expansion device may be located within the indoor unit, the outdoor unit, or both.

[0048] An expansion device can, for example, utilize a throttling effect to lower the temperature and pressure of the refrigerant. The expansion device may include an orifice capable of reducing the cross-sectional area of ​​the flow path. Refrigerant passing through the orifice may experience a decrease in temperature and pressure.

[0049] The expansion device may be implemented as, for example, an electronic expansion valve capable of controlling the opening ratio (the ratio of the cross-sectional area of ​​the valve's flow path when partially open to the cross-sectional area of ​​the valve's flow path when fully open). Depending on the opening ratio of the electronic expansion valve, the amount of refrigerant passing through the expansion device can be controlled.

[0050] The air conditioner may further include a flow diverter valve positioned along the refrigerant circulation path. The flow diverter valve may include, for example, a four-way valve. The flow diverter valve may determine the refrigerant circulation path depending on the indoor unit's operating mode (e.g., cooling operation or heating operation). The flow diverter valve may be connected to the discharge port of the compressor.

[0051] The air conditioner may include an accumulator. The accumulator may be connected to the suction port of the compressor. The accumulator may receive low-temperature, low-pressure refrigerant vaporized in an indoor heat exchanger or an outdoor heat exchanger.

[0052] The accumulator can separate the refrigerant liquid from the refrigerant gas when a refrigerant mixture of refrigerant liquid and refrigerant gas is introduced, and provide the refrigerant gas from which the refrigerant liquid has been separated to the compressor.

[0053] An outdoor fan may be installed near the outdoor heat exchanger. The outdoor fan may blow outdoor air to the outdoor heat exchanger to promote heat exchange between the refrigerant and the outdoor air.

[0054] The outdoor unit of the air conditioner may include at least one sensor. For example, the sensor of the outdoor unit may be provided as an environmental sensor. The outdoor unit sensor may be positioned at any location inside or outside the outdoor unit. For example, the outdoor unit sensor may include a temperature sensor for detecting the air temperature around the outdoor unit, a humidity sensor for detecting the air humidity around the outdoor unit, a refrigerant temperature sensor for detecting the refrigerant temperature of a refrigerant pipe passing through the outdoor unit, or a refrigerant pressure sensor for detecting the refrigerant pressure of a refrigerant pipe passing through the outdoor unit.

[0055] An outdoor unit of an air conditioner may include an outdoor unit communication unit. The outdoor unit communication unit may be configured to receive a control signal from a control unit of an indoor unit of the air conditioner, which will be described later. The outdoor unit may control the operation of a compressor, an outdoor heat exchanger, an expansion device, a flow switching valve, an accumulator, or an outdoor fan based on the control signal received through the outdoor unit communication unit. The outdoor unit may transmit a sensing value detected by an outdoor unit sensor to the control unit of the indoor unit through the outdoor unit communication unit.

[0056] The indoor unit of the air conditioner may include a housing, a blower for circulating air into or out of the housing, and an indoor heat exchanger for exchanging heat with air flowing into the interior of the housing.

[0057] The housing may include an intake port through which indoor air may be drawn into the interior of the housing.

[0058] The indoor unit of the air conditioner may include a filter that is provided to filter foreign substances in the air that flows into the housing through the intake port.

[0059] The housing may include an exhaust port. Air flowing within the housing may be discharged to the exterior of the housing through the exhaust port.

[0060] The housing of the indoor unit may be provided with an airflow guide that guides the direction of air discharged through the exhaust port. For example, the airflow guide may include blades positioned above the exhaust port. For example, the airflow guide may include an auxiliary fan for controlling the exhaust airflow. However, the airflow guide is not limited thereto and may be omitted.

[0061] 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.

[0062] Blowers may include indoor fans and fan motors. For example, indoor fans may include axial fans, diffusion fans, crossflow fans, and centrifugal fans.

[0063] An indoor heat exchanger may be positioned between the blower and the exhaust, or between the intake and the blower. The indoor heat exchanger may absorb heat from air drawn in through the intake or transfer heat to the air drawn in through the intake. The indoor heat exchanger may include heat exchange tubes through which refrigerant flows, and heat exchange fins in contact with the heat exchange tubes to increase the heat transfer surface area.

[0064] The indoor unit of the air conditioner may include a drain tray positioned below the indoor heat exchanger to collect condensate generated in the indoor heat exchanger. The condensate collected in the drain tray may be drained to the outside through a drain hose. The drain tray may be provided to support the indoor heat exchanger.

[0065] The indoor unit of the air conditioner may include an input interface. The input interface may include any type of user input means, including buttons, switches, a touch screen, and / or a touch pad. The user can directly input setting data (e.g., desired indoor temperature, operating mode settings for cooling / heating / dehumidification / air purification, outlet selection settings, and / or air flow settings) through the input interface.

[0066] The input interface may also be connected to an external input device. For example, the input interface may be electrically connected to a wired remote controller. The wired remote controller may be installed at a specific location in an indoor space (e.g., a portion of a wall). A user may input configuration data regarding the operation of the air conditioner by operating the wired remote controller. Electrical signals corresponding to the configuration data obtained through the wired remote controller may be transmitted to the input interface. In addition, the input interface may include an infrared sensor. A user may remotely input configuration data regarding the operation of the air conditioner using a wireless remote controller. The configuration data input through the wireless remote controller may be transmitted to the input interface as an infrared signal.

[0067] Additionally, the input interface may include a microphone. A user's voice command may be acquired through the microphone. The microphone may convert the user's voice command into an electrical signal and transmit the converted electrical signal to an indoor unit control unit. The indoor unit control unit may control components of the air conditioner to execute a function corresponding to the user's voice command. Setting data acquired through the input interface (e.g., desired indoor temperature, operation mode settings for cooling / heating / dehumidification / air purification, outlet selection settings, and / or air volume settings) may be transmitted to the indoor unit control unit, which will be described later. In one example, the setting data acquired through the input interface may be transmitted externally, i.e., to an outdoor unit or a server, through an indoor unit communication unit, which will be described later.

[0068] The indoor unit of the air conditioner may include a power module. The power module may be connected to an external power source to supply power to the components of the indoor unit.

[0069] An indoor unit of an air conditioner may include an indoor unit sensor. The indoor unit sensor may be an environmental sensor positioned in a space inside or outside the housing. For example, the indoor unit sensor may include one or more temperature sensors and / or humidity sensors positioned in a predetermined space inside or outside the housing of the indoor unit. For example, the indoor unit sensor may include a refrigerant temperature sensor for detecting a refrigerant temperature of a refrigerant pipe passing through the indoor unit. For example, the indoor unit sensor may include respective refrigerant temperature sensors for detecting the inlet, middle, and / or outlet temperatures of the refrigerant pipe passing through the indoor heat exchanger.

[0070] 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.

[0071] The indoor unit of the air conditioner may include an indoor unit communication unit. The indoor unit communication unit may include at least one of a short-range communication module and a long-range communication module. The indoor unit communication unit may include at least one antenna for wireless communication with other devices. The outdoor unit may include an outdoor unit communication unit. The outdoor unit communication unit may also include at least one of a short-range communication module and a long-range communication module.

[0072] The short-range wireless communication module may include, but is not limited to, a Bluetooth communication module, a BLE (Bluetooth Low Energy) communication module, a near field communication module, a WLAN (Wi-Fi) communication module, a Zigbee communication module, an infrared (IrDA, infrared Data Association) communication module, a WFD (Wi-Fi Direct) communication module, an UWB (ultrawideband) communication module, an Ant+ communication module, a microwave (μWave) communication module, etc.

[0073] The long-distance communication module may include a communication module that performs various types of long-distance communication and may include a mobile communication unit. The mobile communication unit transmits and receives wireless signals with at least one of a base station, an external terminal, and a server on a mobile communication network.

[0074] The indoor unit communication unit can communicate with external devices such as servers, mobile devices, and other home appliances through a nearby access point (AP). The access point (AP) can connect a local area network (LAN) to which the air conditioner or user device is connected to a wide area network (WAN) to which the server is connected. The air conditioner or user device can be connected to the server through the wide area network (WAN). The indoor unit of the air conditioner may include an indoor unit control unit that controls components of the indoor unit, including a blower, etc. The outdoor unit of the air conditioner may include an outdoor unit control unit that controls components of the outdoor unit, including a compressor, etc. The indoor unit control unit can communicate with the outdoor unit control unit through the indoor unit communication unit and the outdoor unit communication unit. The outdoor unit communication unit can transmit control signals generated by the outdoor unit control unit to the indoor unit communication unit, or transmit control signals transmitted from the indoor unit communication unit to the outdoor unit control unit. In other words, the outdoor unit and the indoor unit can communicate bidirectionally. The outdoor unit and the indoor unit can transmit and receive various signals generated during the operation of the air conditioner.

[0075] The outdoor unit control unit can be electrically connected to components of the outdoor unit and can control the operation of each component. For example, the outdoor unit control unit can adjust the frequency of the compressor and control the flow switching valve to change the circulation direction of the refrigerant. The outdoor unit control unit can adjust the rotation speed of the outdoor fan. In addition, the outdoor unit control unit can generate a control signal to adjust the opening degree of the expansion valve. Under the control of the outdoor unit control unit, the refrigerant can circulate along a refrigerant circulation circuit including the compressor, the flow switching valve, the outdoor heat exchanger, the expansion valve, and the indoor heat exchanger.

[0076] The various temperature sensors included in the outdoor and indoor units can transmit electrical signals corresponding to the detected temperatures to the outdoor unit control unit and / or the indoor unit control unit. For example, the humidity sensors included in the outdoor and indoor units can transmit electrical signals corresponding to the detected humidity to the outdoor unit control unit and / or the indoor unit control unit.

[0077] The indoor unit control unit can obtain user input from a user device, including a mobile device, via the indoor unit communication unit, and can obtain user input directly through the input interface or via a remote controller. The indoor unit control unit can control components of the indoor unit, including a blower, in response to the received user input. The indoor unit control unit can transmit information regarding the received user input to the outdoor unit control unit of the outdoor unit.

[0078] The outdoor unit control unit can control the components of the outdoor unit, including the compressor, based on information regarding user input received from the indoor unit. For example, when a control signal corresponding to a user input for selecting an operation mode, such as cooling operation, heating operation, ventilation operation, defrosting operation, or dehumidification operation, is received from the indoor unit, the outdoor unit control unit can control the components of the outdoor unit so that the air conditioner performs an operation corresponding to the selected operation mode.

[0079] 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.

[0080] The memory can store / remember various information necessary for the operation of the air conditioner. The memory can store instructions, applications, data, and / or programs necessary for the operation of the air conditioner. For example, the memory can store various programs for cooling, heating, dehumidifying, and / or defrosting operations of the air conditioner. The memory can include volatile memory, such as Static Random Access Memory (S-RAM) and Dynamic Random Access Memory (DRAM), for temporarily storing data. In addition, the memory can include nonvolatile memory, such as Read Only Memory (ROM), Erasable Programmable Read Only Memory (EPROM), and Electrically Erasable Programmable Read Only Memory (EEPROM), for storing data for a long period of time.

[0081] The processor can generate control signals for controlling the operation of the air conditioner based on instructions, applications, data, and / or programs stored in memory. The processor, as hardware, may include logic circuits and arithmetic circuits. The processor can process data according to programs and / or instructions provided from the memory and generate control signals based on the processing results. The memory and the processor may be implemented as a single control circuit or as multiple circuits.

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

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

[0084] Fig. 8 is a schematic perspective view of a conventional heat exchanger. Fig. 9 is a drawing showing the flow of refrigerant within the connection header of the conventional heat exchanger illustrated in Fig. 8. Referring to Fig. 8, the conventional heat exchanger has a plurality of heat transfer tubes arranged vertically in parallel, and upper and lower connection headers connected to one end of the plurality of heat transfer tubes. Refrigerant flowing through the plurality of heat transfer tubes arranged at the lower side (first stage) among the plurality of heat transfer tubes flows into the plurality of heat transfer tubes arranged at the upper side (second stage) through the upper and lower connection headers. As illustrated in Fig. 9, in the conventional heat exchanger illustrated in Fig. 8, the gas-liquid two-phase refrigerant in the space within the upper and lower connection headers is separated into gas-phase refrigerant and liquid-phase refrigerant, and thus, a so-called liquid pool, in which the liquid-phase refrigerant accumulates in the space, may occur. The liquid pool mainly occurs in the lower region of the space within the upper and lower connection headers. When liquid accumulation occurs, the two-phase refrigerant (gas-liquid) is unevenly distributed across multiple heat transfer tubes on the downstream side (second stage). This can cause maldistribution of the refrigerant in the heat exchanger, reducing heat exchange efficiency.

[0085] The present disclosure provides an air conditioner capable of improving the heat exchange efficiency of a heat exchanger. The present disclosure provides an air conditioner including a heat exchanger capable of evenly flowing refrigerant through a plurality of upstream heat transfer tubes and a plurality of downstream heat transfer tubes connected by a connection header. However, the technical problem to be achieved in the present disclosure is not limited to the technical problem mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which the present disclosure pertains from the description below. Hereinafter, embodiments of an air conditioner including a heat exchanger will be described with reference to the drawings.

[0086] FIG. 7 is a schematic diagram of an embodiment of an air conditioner according to the present disclosure. Referring to FIG. 7, the air conditioner may include an indoor heat exchanger (201), a compressor (202), an outdoor heat exchanger (203), and an expansion device (204). The indoor heat exchanger (201), the compressor (202), the outdoor heat exchanger (203), and the expansion device (204) may be connected by a refrigerant pipe. The outdoor heat exchanger (203) is installed in the outdoor unit and may perform heat exchange between the refrigerant and the outdoor air by utilizing a phase change of the refrigerant (e.g., evaporation or condensation). For example, while the refrigerant condenses in the outdoor heat exchanger (203), the refrigerant may release heat to the outdoor air, and while the refrigerant flowing in the outdoor heat exchanger (203) evaporates, the refrigerant may absorb heat from the outdoor air. An indoor heat exchanger (201) is installed in the indoor unit and can perform heat exchange between the refrigerant and indoor air by utilizing a phase change (e.g., evaporation or condensation) of the refrigerant. For example, while the refrigerant evaporates in the indoor heat exchanger (201), 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 (201). In addition, while the refrigerant condenses in the indoor heat exchanger (201), 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 (201). The compressor (202) compresses the refrigerant gas between the indoor heat exchanger (201) and the outdoor heat exchanger (203). The expansion device (204) reduces the pressure of the refrigerant between the indoor heat exchanger (201) and the outdoor heat exchanger (203). When cooling, the refrigerant circulates in the order of a compressor (202), an outdoor heat exchanger (203), an expansion device (204), and an indoor heat exchanger (201), with the outdoor heat exchanger (203) functioning as a condenser and the indoor heat exchanger (201) functioning as an evaporator.During heating, the air circulates in the order of a compressor (202), an indoor heat exchanger (201), an expansion device (204), and an outdoor heat exchanger (203), with the outdoor heat exchanger (203) functioning as an evaporator and the indoor heat exchanger (201) functioning as a condenser. The embodiments of the heat exchanger (100) described below can be applied to the indoor heat exchanger (201) and / or the outdoor heat exchanger (203).

[0087] Fig. 1 is a schematic perspective view showing the overall configuration of a heat exchanger (100) according to one embodiment of the present disclosure. Fig. 2 is a schematic front view of the heat exchanger (100) according to one embodiment of the present disclosure illustrated in Fig. 1. Fig. 3 is a drawing showing the first and second rows of the heat exchanger (100) according to one embodiment of the present disclosure illustrated in Fig. 1 separately. The heat exchanger (100) constitutes a refrigerant circuit of an air conditioner and can be applied to either or both of the outdoor heat exchanger (203) and the indoor heat exchanger (201) described above.

[0088] Referring to FIGS. 1 to 3, a heat exchanger (100) may have a plurality of heat exchange parts (1) and one or more connection parts (2). The heat exchanger (1) further has an inlet pipe (3) and a discharge pipe (4). Each of the plurality of heat exchange parts (1) has a plurality of heat transfer pipes (10) through which a refrigerant flows. The plurality of heat transfer pipes (10) may be parallel to each other. One or more connection parts (2) connect the plurality of heat exchange parts (1) in series. The connection part (2) connects two adjacent heat exchange parts (1) to each other. A plurality of heat exchange parts (1) are connected to each other in series, for example, by the plurality of connection parts (2), thereby forming a plurality of refrigerant passages. At least one of the plurality of connection parts (2) may connect two adjacent heat exchange parts (1) such that at least one of the plurality of refrigerant passages does not merge with another refrigerant passage. At least one of the above plurality of connecting parts (2) can connect two adjacent heat exchange parts (1) so that not all of the plurality of refrigerant passages join each other.

[0089] Refrigerant is introduced into a plurality of heat exchangers (1) through an introduction pipe (3). The introduction pipe (3) is connected to one of a plurality of heat exchange units (1). Refrigerant is discharged from the plurality of heat exchange units (1) through a discharge pipe (4). The discharge pipe (4) is connected to a heat exchange unit other than the heat exchange unit to which the introduction pipe (3) is connected among the plurality of heat exchange units (1). The refrigerant introduced into the heat exchanger (100) through the introduction pipe (3) flows along the refrigerant path and is discharged from the heat exchanger (100) through the discharge pipe (4).

[0090] Hereinafter, the arrangement direction of the plurality of heat transfer tubes (10) is referred to as the vertical direction, the extension direction of the heat transfer tubes (10) is referred to as the left-right direction, and the direction orthogonal to the up-down direction and the left-right direction is referred to as the front-back direction. The front-back direction is the direction in which air that exchanges heat with the refrigerant in the heat exchanger (100) flows.

[0091] For example, when the heat exchanger (100) functions as a condenser, among the plurality of heat exchange units (1) arranged in two rows in the front-back direction, the heat exchange unit (1) on the upstream side (the side where the inlet pipe (3) is installed) may be arranged on the leeward side, and the heat exchange unit (1) on the downstream side (the side where the discharge pipe (4) is installed) may be arranged on the windward side. For example, when the heat exchanger (100) functions as an evaporator, among the plurality of heat exchange units (1) arranged in two rows in the front-back direction, the heat exchange unit (1) on the upstream side (the side where the inlet pipe (3) is installed) may be arranged on the leeward side, and the heat exchange unit (1) on the downstream side (the side where the discharge pipe (4) is installed) may be arranged on the windward side.

[0092] The heat exchanger (1) has a plurality of heat transfer tubes (10). Referring to FIGS. 1 to 3, the plurality of heat transfer tubes (10) extend left and right and can be arranged in parallel in the vertical direction at a predetermined interval. The heat transfer tubes (10) may have a flat tube shape. The upper and lower surfaces of the heat transfer tubes (10) may be flat surfaces, and the plurality of heat transfer tubes (10) may be arranged in the vertical direction with their flat surfaces facing each other. The heat transfer tubes (10) may be porous tubes having a plurality of refrigerant flow paths formed therein through which refrigerant flows. The refrigerant flow paths may be formed by extending in the extension direction of the heat transfer tubes (10), for example, in the left and right directions.

[0093] Refrigerant is introduced into a plurality of heat transfer tubes (10) through one of the left and right ends of the heat exchange unit (1), that is, one of the first end (11) and the second end (12). Accordingly, refrigerant flows in the same direction through the plurality of heat transfer tubes (10) included in one heat exchange unit (1).

[0094] As described above, the heat exchanger (100) has a plurality of heat exchange parts (1). For example, the heat exchanger (100) of the present embodiment has six heat exchange parts (1). Each of the plurality of heat exchange parts (1) has a plurality of heat transfer tubes (10). The plurality of heat exchange parts (1) may each have the same number of heat transfer tubes (10). For example, the plurality of heat exchange parts (1) of the present embodiment have six heat transfer tubes (10). The heat transfer tubes (10) included in the plurality of heat exchange parts (1) may have substantially the same dimensions (length, width, thickness). Here, substantially the same means that the error in the dimensions of the heat transfer tubes (10) is ±1%.

[0095] Hereinafter, when there is no need to distinguish between the six heat exchange units, for example, when explaining matters common to the six heat exchange units, the reference number indicating the heat exchange unit is indicated as "1". When there is a need to distinguish between the six heat exchange units, the six heat exchange units are distinguished from each other by attaching reference numbers 1A, 1B, 1C, 1D, 1E, and 1F. In addition, the heat transfer tubes included in each heat exchange unit (1A, 1B, 1C, 1D, 1E, and 1F) are distinguished from each other by attaching reference numbers 10A, 10B, 10C, 10D, 10E, and 10F. When there is no need to distinguish between the heat transfer tubes included in the heat exchange section (1A, 1B, 1C, 1D, 1E, 1F), for example, when explaining matters common to the heat transfer tubes of all heat exchange sections, the reference number indicating the heat transfer tube is indicated as "10".

[0096] For example, referring to FIGS. 1 to 3, the heat exchange units (1A, 1B, 1C, 1D, 1E, 1F) may have an arrangement structure of three upper and lower stages and two front and rear rows. The heat exchange units (1A, 1B, 1C, 1D, 1E, 1F) are arranged in three rows in the upper and lower direction and in two rows in the front and rear direction so that the extension directions of the respective heat transfer tubes (10A, 10B, 10C, 10D, 10E, 10F), i.e., the flow directions of the refrigerant, are parallel to each other. In other words, the heat exchange units (1A, 1B, 1C) arranged in three rows in the upper and lower direction and the heat exchange units (1D, 1E, 1F) arranged in two rows in the front and rear direction. In the heat exchange units (1A, 1B, 1C) and heat exchange units (1D, 1E, 1F), the vertical stages are referred to as the first stage, the second stage, and the third stage from bottom to top. That is, in the heat exchange units (1A, 1B, 1C) and heat exchange units (1D, 1E, 1F), the first stages are the heat exchange unit (1A) and the heat exchange unit (1F), respectively. In addition, the heat exchange units (1A, 1B, 1C) arranged at the front in the front-to-back direction are referred to as the first row, and the heat exchange units (1D, 1E, 1F) arranged at the back are referred to as the second row. The two heat exchange units of the same stage, the heat exchange units (1A, 1B, 1C) of the first row and the heat exchange units (1D, 1E, 1F) of the second row, are arranged adjacent to each other in the front-to-back direction at the same height. For example, the heat exchanger (1A) of the first stage of the first row is arranged adjacent to the heat exchanger (1F) of the first stage of the second row at the same height in the front-back direction. In addition, the heat transfer tubes (10A, 10B, 10C) of the heat exchanger (1A, 1B, 1C) of the first row and the heat transfer tubes (10D, 10E, 10F) of the heat exchanger (1D, 1E, 1F) of the second row are arranged to correspond one-to-one in the front-back direction at the same height. That is, the heat transfer tubes (10A) of the heat exchanger (1A) of the first stage of the first row are arranged to correspond one-to-one in the front-back direction at the same height with the heat transfer tubes (10F) of the heat exchanger (1F) of the first stage of the second row.

[0097] Referring to FIGS. 1 to 3, a connecting portion (2) connects two heat exchange units (1) adjacent to each other in a vertical direction or a front-back direction. That is, the connecting portion (2) provides a connecting passage so that refrigerant can move from one heat exchange unit (1) to another heat exchange unit (1) adjacent to it in a vertical direction or a front-back direction. The connecting portion (2) connects the two left and right ends of the two adjacent heat exchange units (1).

[0098] The connecting portion (2) connects the downstream ends of the heat transfer tubes (10) of the heat exchanger (1) located on the upstream side among two adjacent heat exchange units (1) and the upstream ends of the heat transfer tubes (10) of the heat exchanger (1) located on the downstream side. The connecting portion (2) changes the flow direction of the refrigerant flowing along the heat transfer tubes (10) of the upstream heat exchanger (1) and causes it to flow into the heat transfer tubes (10) of the downstream heat exchanger (1). Here, changing the flow direction means that the flow direction of the refrigerant flowing into the connecting portion (2) and the flow direction of the refrigerant discharged from the connecting portion (2) become opposite to each other. Therefore, the refrigerants flow in opposite directions within the two heat exchange units (1) connected to each other by the connecting portion (2). In other words, the refrigerant flows in the first direction along the heat transfer tubes (10) of the upstream heat exchanger (1), and the refrigerant flows in the second direction, which is the opposite direction to the first direction, along the heat transfer tubes (10) of the downstream heat exchanger (1).

[0099] For example, the heat exchanger (100) of the present embodiment has five connecting portions (2), and six heat exchange portions (1A, 1B, 1C, 1D, 1E, 1F) are sequentially connected in series by the five connecting portions (2). For example, the connecting portions (2) may have an up-and-down switching connecting portion (2X) that switches the flow direction of the refrigerant in an up-and-down direction, and a horizontal switching connecting portion (2Y) that switches the flow direction in a horizontal direction, for example, in a front-to-back direction. The up-and-down switching connecting portion (2X) connects the left and right ends of two heat exchange portions (1) that are adjacent to each other in the up-and-down direction. In other words, the up-and-down switching connecting portion (2X) connects the first heat exchange portion and the second heat exchange portion that are adjacent to each other in the up-and-down direction. The up-and-down switching connecting portion (2X) connects the downstream end of the first heat exchange portion, which is located relatively upstream, and the upstream end of the second heat exchange portion, which is located relatively downstream. The refrigerant flowing in the first direction inside the plurality of first heat transfer tubes of the first heat exchange unit is introduced into the plurality of second heat transfer tubes of the second heat exchange unit by the upper and lower switching connection parts (2X) and flows in the second direction, which is the opposite direction to the first direction. The horizontal switching connection part (2Y) connects the left and right end parts of two heat exchange units (1) that are adjacent to each other in the front-back direction. In other words, the horizontal switching connection part (2Y) connects the second heat exchange unit and the third heat exchange unit that are adjacent to each other in the front-back direction. The horizontal switching connection part (2Y) connects the downstream end of the second heat exchange unit that is located relatively upstream and the upstream end of the third heat exchange unit that is located relatively downstream. The refrigerant flowing in the second direction inside the plurality of second heat transfer tubes of the second heat exchange unit is introduced into the plurality of third heat transfer tubes of the third heat exchange unit by the horizontal switching connection part (2Y) and flows in the first direction, which is the opposite direction to the second direction. In this embodiment, the connecting portion (2) has four upper and lower switching connecting portions (2X) and one horizontal switching connecting portion (2Y).

[0100] Referring to FIGS. 1 to 3, refrigerant is introduced into a heat exchanger (100) through an introduction pipe (3). The introduction pipe (3) is connected to a first end (11) or a second end (12) of one heat exchanger (1) among a plurality of heat exchanger units (1), and refrigerant is introduced into a plurality of heat transfer tubes (10) of the heat exchanger unit (1) through the introduction pipe (3). In the present embodiment, the introduction pipe (3) is connected to a second end (12) of the heat exchanger unit (1A) to distribute refrigerant to the heat transfer tubes (10A). For example, one introduction pipe (3) is connected to a classifier (5) installed in the second end (12) of the heat exchanger unit (1A), and the refrigerant introduced through the introduction pipe (3) is classified into six heat transfer tubes (10A) through the classifier (5).

[0101] Referring to FIGS. 1 to 3, refrigerant is discharged from the heat exchanger (100) through the discharge pipe (4). The discharge pipe (4) is connected to the first end (11) or the second end (12) of one of the plurality of heat exchange units (1) other than the heat exchange unit (1) to which the introduction pipe (3) is connected, and refrigerant is discharged to the outside from the plurality of heat transfer pipes (10) of the heat exchange unit (1) through the discharge pipe (4). In the present embodiment, the discharge pipe (4) is connected to the second end (12) of the heat exchange unit (1F), and refrigerant is discharged to the outside from the heat transfer pipes (10F) through the discharge pipe (4). For example, six discharge pipes (4) are provided, and six heat transfer pipes (10F) and six discharge pipes (4) correspond one-to-one. The refrigerant flowing along the six heat pipes (10F) is discharged to the outside through the corresponding six discharge pipes (4).

[0102] A plurality of heat exchange units (1) are connected in series through one or more connecting portions (2), thereby forming a series of multiple refrigerant passages through which refrigerant flows. In the present embodiment, six heat exchange units (1A, 1B, 1C, 1D, 1E, 1F) are sequentially connected through five connecting portions (2), thereby forming a series of multiple refrigerant passages.

[0103] The refrigerant is introduced into the heat exchanger (1A) on the most upstream side of the refrigerant path through the introduction pipe (3), passes through the heat exchangers (1B, 1C, 1D, 1E, 1F), and is discharged from the heat exchanger (1F) on the most downstream side through the discharge pipe (4).

[0104] As an example, the appearance of the change in state of the refrigerant when the heat exchanger (100) functions as a condenser is described with reference to FIG. 3.

[0105] First, the gaseous refrigerant flows into the classifier (5) through the introduction pipe (3), is classified in the classifier (5), and is introduced into the plurality of heat transfer tubes (10A) of the heat exchange unit (1A) of the first row, first stage. The gaseous refrigerant, which has exchanged heat with air while passing through the plurality of heat transfer tubes (10A), for example, from left to right, comes out from the plurality of heat transfer tubes (10A) and is introduced into the plurality of heat transfer tubes (10B) of the heat exchange unit (1B) of the first row, second stage through the upper and lower switching connection (2X), for example, the upper and lower switching connection (2X-AB).

[0106] For example, the refrigerant can be phase-changed from a gaseous state to a gas-liquid two-phase state in the heat exchange unit (1B). The two-phase refrigerant, which has exchanged heat with air while passing through the plurality of heat transfer tubes (10B) from right to left, is sequentially introduced into the plurality of heat transfer tubes (10C) of the first row, third stage heat exchange unit (1C) through the upper and lower switching connection (2X-BC), into the plurality of heat transfer tubes (10D) of the second row, third stage heat exchange unit (1D) through the horizontal switching connection (2Y), into the plurality of heat transfer tubes (10E) of the second row, second stage heat exchange unit (1E) through the upper and lower switching connection (2X-DE), and into the plurality of heat transfer tubes (10F) of the second row, first stage heat exchange unit (1F) through the upper and lower switching connection (2X-EF). For example, the refrigerant can be phase-changed from a gas-liquid two-phase state to a liquid state in the heat exchange unit (1F). The liquid refrigerant flowing along the plurality of heat pipes (10F) is discharged to the outside through the discharge pipe (4).

[0107] As an example, in order to increase the temperature difference between the refrigerant flowing along the plurality of heat pipes (10) and the air passing through the plurality of heat exchange units (1) as much as possible in each row of the plurality of heat exchange units (1) arranged in two rows in the front-back direction, the heat exchange units (1A, 1B, 1C) of the first row on the upstream side of the refrigerant flow path may be arranged on the leeward side, and the heat exchange units (1D, 1E, 1F) of the second row on the downstream side may be arranged on the windward side.

[0108] As one embodiment, each of the plurality of connecting portions (2) may be provided with a plurality of connecting passages (20) that individually connect a plurality of heat transfer tubes (10) of a heat exchange portion (1) located on the upstream side among two adjacent heat exchange portions (1) with a plurality of heat transfer tubes (10) of a heat exchange portion (1) located on the downstream side. Each connecting portion (2) may include a plurality of connecting passages (20) that are independent of each other. The plurality of connecting passages (20) may connect a plurality of heat transfer tubes (10) of a heat exchange portion (1) located on the upstream side with a plurality of heat transfer tubes (10) of a heat exchange portion (1) located on the downstream side in a one-to-one relationship. The horizontal switching connection (2Y) may include a plurality of horizontal connecting passages (20) (Fig. 1: 20Y), and the upper and lower switching connection (2X) may include a plurality of upper and lower connecting passages (20) (Fig. 4, Fig. 6: 20X).

[0109] For example, a plurality of connecting passages (20) may be formed in the form of a plurality of cavities in the internal space of a connecting portion (2) composed of a block body. The number of cavities may be the same as the number of a plurality of heat transfer pipes (10). For example, a plurality of connecting passages (20) may include the same number of pipe members as a plurality of heat transfer pipes (10). In the present embodiment, six independent connecting passages (20) are formed in the connecting portion (2), and six heat transfer pipes (10) of a heat exchanger (1) located on the upstream side and six heat transfer pipes (10) of a heat exchanger (1) located on the downstream side are connected in a one-to-one relationship.

[0110] In one embodiment, the plurality of connecting portions (2) may connect the plurality of heat exchange units (1) so that the lengths of the plurality of refrigerant passages are substantially the same. Here, substantially the same means that the error in the lengths of the plurality of refrigerant passages is ±1%. In one embodiment, the lengths of the plurality of connecting passages (20) may be substantially the same. Here, substantially the same means that the error in the lengths of the plurality of connecting passages (20) is ±1%. In one embodiment, the plurality of connecting passages (20) may connect two heat transfer tubes (10) located at the same vertical arrangement position (for example, the same stage counting from the top or bottom) in two adjacent heat exchange units (1).

[0111] For example, FIG. 4 is a schematic enlarged view of a connection part (2) according to one embodiment of the present disclosure. Referring to FIG. 4, six upper and lower connection passages (20X) installed in the upper and lower switching connection part (2X-AB) connect six heat transfer tubes (10A) of the heat exchange part (1A) and six heat transfer tubes (10B) of the heat exchange part (1B), thereby connecting the heat transfer tubes (10A) and (10B) positioned at the same position in the upper and lower direction to each other. For example, in FIG. 4, one of the six upper and lower connection passages (20X) connects the heat transfer tube (10A) arranged first from the top in the heat exchange part (1A) and the heat transfer tube (10B) arranged first from the top in the heat exchange part (1B). Also, referring to FIG. 1, six horizontal connecting passages (20Y) installed in the horizontal conversion connection (2Y) connect six heat transfer tubes (10C) of the heat exchange unit (1C) and six heat transfer tubes (10D) of the heat exchange unit (1D), connecting the heat transfer tubes (10C) (10D) positioned at the same position in the vertical direction. For example, one of the six horizontal connecting passages (20Y) connects the heat transfer tube (10C) arranged third from the bottom in the heat exchange unit (1C) and the heat transfer tube (10D) arranged third from the bottom in the heat exchange unit (1D). As a result, in the present embodiment, six independent refrigerant passages passing through the six heat exchange units (1) and having substantially the same passage length can be formed.

[0112] When the temperature difference between adjacent heat transfer tubes (10) of the heat exchange unit (1) is large, heat exchange occurs between the adjacent heat transfer tubes (10). This hinders heat exchange between the refrigerant flowing along the heat transfer tubes (10) and air, which reduces heat exchange efficiency. According to the heat exchanger (100) according to one embodiment of the present disclosure, refrigerant having the same temperature flows through a plurality of heat transfer tubes (10) arranged vertically in each heat exchange unit (1). Therefore, the temperature difference between adjacent heat transfer tubes (10) in each heat exchange unit (1) is suppressed, heat exchange between adjacent heat transfer tubes (10) is suppressed, and heat loss due to heat exchange between adjacent heat transfer tubes (10) can be suppressed.

[0113] The refrigerant that has passed through the plurality of heat transfer tubes (10) of the upstream heat exchanger (1) is not combined or separated, but flows into the corresponding plurality of heat transfer tubes (10) of the adjacent downstream heat exchanger (1) through the plurality of connecting passages (20) of the connecting portion (2). Even when the gas-liquid two-phase refrigerant flows into the plurality of heat transfer tubes (10) of the upstream heat exchanger (1), the heat exchange efficiency of the heat exchanger (100) can be maintained because the gas-liquid two-phase refrigerant is evenly introduced into the corresponding plurality of heat transfer tubes (10) of the downstream heat exchanger (1).

[0114] Since the plurality of connecting channels (20) connect two heat transfer tubes (10) in the same arrangement position in two adjacent heat exchange units (1) in a one-to-one relationship, it is easy to make the lengths of the plurality of refrigerant channels formed by the plurality of heat transfer tubes (10) of the plurality of heat exchange units (1) almost identical.

[0115] Since the plurality of connecting passages (20) of the connecting portion (2) connecting two adjacent heat exchangers (1) have passage lengths that are almost identical to each other, it is difficult for a difference in pressure loss to occur in the plurality of refrigerant passages, and thus maldistribution of the refrigerant can be reduced.

[0116] Since the introduction pipe (3) and the discharge pipe (4) are arranged on either side of the left or right direction of the heat exchanger (100), piping work, etc., is simple. For example, in the above-described embodiment, the introduction pipe (3) and the discharge pipe (4) are arranged on the second end (12) of the first row, first stage heat exchanger (1A) and the second end (12) of the second row, first stage heat exchanger (1F), respectively.

[0117] In the embodiment of the heat exchanger (100) described above, the plurality of refrigerant passages are not joined or separated in all of the plurality of connection portions (2), but this is not limited thereto. It is sufficient that the plurality of refrigerant passages are not joined or separated in at least one of the plurality of connection portions (2). In addition, the plurality of connection portions (2) may be provided with at least one connection passage (20) that individually connects one heat transfer tube (10) of one heat exchange unit (1) with one heat transfer tube of another adjacent heat exchange unit (1), and according to this, the occurrence of drift in the refrigerant passage formed by two heat transfer tubes (10) connected to each other by at least one connection passage (20) can be suppressed, thereby exerting an effect of maintaining heat exchange efficiency.

[0118] The number of heat exchanger parts (1) included in the heat exchanger (100) does not necessarily have to be six, and may be multiple, i.e., two or more. In addition, at least two of the multiple heat exchanger parts (1) are arranged adjacent to each other in the vertical direction and connected by a vertical conversion connection part (2X) in which a junction and a classifier are not installed. In addition, the arrangement method (single or multiple) of the heat exchanger parts (1) may be appropriately determined according to the purpose.

[0119] The heat exchanger (100) can function not only as a condenser but also as an evaporator. In this case, the first row of heat exchangers (1) upstream of the refrigerant flow path can be arranged on the windward side, and the second row of heat exchangers (1) downstream can be arranged on the leeward side. Accordingly, the temperature difference between the refrigerant passing through the heat exchanger (100) and the air can be increased, thereby improving heat exchange efficiency.

[0120] FIG. 5 is a drawing showing the first and second rows of a heat exchanger according to one embodiment of the present disclosure separately. Referring to FIG. 5, the heat exchanger (100) of the present embodiment may be provided with a dummy heat transfer tube (6) disposed between two heat exchange parts (1) that are vertically adjacent to each other. The dummy heat transfer tube (6) is a heat transfer tube through which no refrigerant flows. The number of dummy heat transfer tubes (6) may be one or two or more. The dummy heat transfer tube (6) is, for example, a heat transfer tube that does not communicate with the connection path (20) of the connection part (2). The dummy heat transfer tube (6) may be a tube that blocks a refrigerant flow path inside a typical heat transfer tube.

[0121] According to this configuration, heat exchange between two heat exchange parts (1) adjacent to each other vertically can be reduced or blocked by the dummy heat transfer tube (6), so that the heat exchange efficiency of the heat exchanger (100) can be maintained. When a gas-liquid two-phase refrigerant flows in one of the two adjacent heat exchange parts (1) and a gas- or liquid-phase refrigerant flows in the other, the temperature difference between these heat exchange parts (1) is relatively large, so a dummy heat transfer tube (6) can be installed between these two heat exchange parts (1). For example, as illustrated in FIG. 5, a dummy heat transfer tube (6) can be installed between a heat exchange part (1A) in which a gas-phase refrigerant flows and a heat exchange part (1B) in which a gas-liquid two-phase refrigerant flows, and between a heat exchange part (1E) in which a gas-liquid two-phase refrigerant flows and a heat exchange part (1F) in which a liquid-phase refrigerant flows.

[0122] A heat exchange system can be configured by stacking two or more heat exchangers (100) according to the above-described embodiments in a vertical direction. In this case, two heat exchangers (100) adjacent to each other vertically can be stacked so as to have a planar symmetrical relationship with each other when viewed in a horizontal direction. For example, the first row of the lower heat exchanger (100) can be arranged in the order of heat exchangers (1A, 1B, 1C) from the bottom to the top, and the first row of the upper heat exchanger (100) can be arranged in the order of heat exchangers (1C, 1B, 1A) from the bottom to the top. According to this configuration, since the two identical heat exchange parts (1C) of the two heat exchangers (100) are arranged adjacent to each other, the temperature difference at the boundary between the two heat exchangers (100) can be reduced, and thereby heat loss due to heat exchange between the two heat exchangers (100) can be reduced.

[0123] In the above-described embodiments, the introduction pipe (3) is connected to the heat exchanger (1A), but the introduction pipe (3) may also be connected to the heat exchanger (1F). In this case, the discharge pipe (4) may be connected to the heat exchanger (1A).

[0124] In the above-described embodiments, the upper and lower connecting passages (20X) connect two heat transfer tubes (10) that are arranged in the same position in two adjacent heat exchange units (1), but are not limited thereto. The upper and lower connecting passages (20X) may also connect two heat transfer tubes (10) that are arranged in different positions in two heat exchange units (1).

[0125] Fig. 6 is a schematic enlarged view of a connection part (2) according to one embodiment of the present disclosure. Referring to Fig. 6, a plurality of connection paths (20X) of an upper and lower switching connection part (2X) connect two heat transfer tubes (10) positioned at positions that are symmetrical to each other in the upper and lower directions when connecting a plurality of heat transfer tubes (10) of a lower heat exchanger (10) and a plurality of heat transfer tubes (10) of an upper heat exchanger (10). For example, in Fig. 6, a heat exchanger (1A) of the first row, first stage, and a heat exchanger (1B) of the first row, second stage, are connected to each other by an upper and lower switching connection part (2X-AB). Six heat transfer tubes (10A) of the heat exchanger (1A) of the first row, first stage, are sequentially denoted as ①②③④⑤⑥ from the top, and six heat transfer tubes (10B) of the heat exchanger (1B) of the first row, second stage, are sequentially denoted as ①②③④⑤⑥ from the top. The six connecting passages (20X) connect six heat transfer tubes (10A) and six heat transfer tubes (10B) in pairs as follows: ①-⑥, ②-⑤, ③-④, ④-③, ⑤-②, ⑥-①. Similarly, the six connecting passages (20X) of the upper and lower switching connection (2X-BC) connecting the first row, second stage heat exchanger (1B) and the first row, third stage heat exchanger (1C) connect six heat transfer tubes (10B) and six heat transfer tubes (10C) in pairs as follows: ①-⑥, ②-⑤, ③-④, ④-③, ⑤-②, ⑥-①.

[0126] According to this configuration, each of the six refrigerant passages passing through the heat exchangers (1A, 1B, 1C) includes two connecting passages (20X), and the sum of the lengths of the two connecting passages (20X) included in each of the six refrigerant passages is almost the same. Therefore, the lengths of the six refrigerant passages passing through the heat exchangers (1A, 1B, 1C) can all be made almost the same. Therefore, since the path lengths of the plurality of refrigerant passages can be made almost the same relatively simply, the difference in pressure loss in each refrigerant passage can be reduced, thereby alleviating drift.

[0127] In embodiments of the heat exchanger (100), among the plurality of heat exchange units (1) arranged in the front-back direction and up-down direction, an introduction pipe (3) is connected to a heat exchange unit (1A) of the front row (first row), and a discharge pipe (4) is connected to a heat exchange unit (1F) of the rear row (second row). That is, the introduction pipe (3) and the discharge pipe (4) are respectively connected to two heat exchange units (1) belonging to different rows in the front-back direction. However, the arrangement of the introduction pipe (3) and the discharge pipe (4) is not limited to this.

[0128] Fig. 10 is a schematic perspective view showing the overall configuration of a heat exchanger (201) according to one embodiment of the present disclosure. Fig. 11 is a schematic front view and a rear view of the heat exchanger (201) according to one embodiment of the present disclosure illustrated in Fig. 10. The heat exchanger (201) of the present embodiment may be an indoor heat exchanger installed indoors, and the following describes a case where the indoor heat exchanger (201) functions as an evaporator. The indoor heat exchanger (201) of the present embodiment has an inlet pipe (3) and an outlet pipe (4) that belong to the same row and are connected to two heat exchange parts (1) that belong to different stages in the vertical direction.

[0129] Referring to FIGS. 10 and 11, the indoor heat exchanger (201) may be provided with a plurality of heat exchange units (1) arranged in the front-rear direction and the up-down direction, and a plurality of connection units (2) that connect the plurality of heat exchange units (1) in series to form a refrigerant passage (L). An introduction pipe (3) is connected to one of the plurality of heat exchange units (1) to introduce refrigerant into one end of the refrigerant passage (L). A discharge pipe (4) that discharges refrigerant from the other end of the refrigerant passage (L) is connected to another of the plurality of heat exchange units (1). For example, referring to FIGS. 10 and 11, four heat exchange units (1G, 1H, 1I, 1J) and three connection units (2) are illustrated.

[0130] In the present embodiment, air for heat exchange with the refrigerant of the indoor heat exchanger (201) flows from the heat exchanger (1G, 1H) located in the front row (first row) among the plurality of heat exchange units (1) arranged in the front-back direction toward the heat exchanger (1I, 1J) located in the back row (second row). Hereinafter, the front row (first row) side is also referred to as the windward side, and the back row (second row) side is also referred to as the leeward side. Since the configuration of each of the plurality of heat exchange units (1G to 1J) is the same as the heat exchange unit (1) of the above-described embodiment, redundant description is omitted. The four heat exchange units (1G to 1J) are arranged in two stages in the vertical direction and in two rows in the front-back direction so that the extension directions of the respective heat transfer tubes (10) are parallel to each other. In addition, the number of heat exchange units (1) forming the heat exchanger (201) is not limited to four. A plurality of heat exchange units (1) can be arranged in two or more rows front to back and two or more rows up and down. The two heat exchange units (1G, 1H) arranged in the vertical direction in the first row located on the windward side are grouped together and called a windward heat exchange unit group (14), and the two heat exchange units (1I, 1J) arranged in the vertical direction in the second row located on the windward side are grouped together and called a windward heat exchange unit group (15).

[0131] The connecting portion (2) individually connects the heat transfer tubes (10) of two adjacent heat exchange units (1). In the present embodiment, the connecting portion (2) has one upper and lower switching connecting portion (2X) and two horizontal switching connecting portions (2Y). The upper and lower switching connecting portion (2X) connects the heat exchange unit (1I) and the heat exchange unit (1J). The horizontal switching connecting portion (2Y) may have a horizontal switching connecting portion (2Y-GI) that connects the heat exchange unit (1G) and the heat exchange unit (1I) and a horizontal switching connecting portion (2Y-JH) that connects the heat exchange unit (1J) and the heat exchange unit (1H).

[0132] The inlet pipe (3) and the discharge pipe (4) are connected to the heat exchange unit group (14) on the windward side. The inlet pipe (3) is connected to the heat exchange unit (1G) arranged in the first stage of the heat exchange unit group (14) on the windward side, and the discharge pipe (4) is connected to the heat exchange unit (1H) arranged in the second stage, and the discharge pipe (4) is arranged above the inlet pipe (3) in the vertical direction.

[0133] According to this configuration, the refrigerant introduced into the heat exchange unit (1G) through the introduction pipe (3) passes through the heat exchange unit (1I), the heat exchange unit (1J), and the heat exchange unit (1H) in sequence and is discharged from the discharge pipe (4).

[0134] Fig. 12 is a schematic diagram of an embodiment of an air conditioner (AC) according to the present disclosure. Referring to Fig. 12, the air conditioner (AC) may be equipped with an indoor heat exchanger (201), an outdoor heat exchanger (203), a compressor (202), an expansion valve (expansion device) (204), and a toll switching valve (not shown). The indoor heat exchanger (201), the outdoor heat exchanger (203), the compressor (202), the expansion valve (204), and the toll switching valve are connected by a refrigerant pipe to form a refrigerant circuit (R). The air conditioner (AC) may be equipped with a flow control unit (400) that controls the flow rate of the refrigerant flowing in the refrigerant circuit (R). Fig. 11 shows the flow direction of the refrigerant when the heat exchanger (201) functions as an evaporator, i.e., when the air conditioner (AC) is in cooling operation. The air conditioner (AC) can be controlled so that the superheat of the refrigerant discharged from the discharge pipe (4) of the indoor heat exchanger (201) functioning as an evaporator is higher than a predetermined value.

[0135] The indoor heat exchanger (201) can be installed inside the casing of an indoor unit installed inside a building, and the outdoor heat exchanger (203), compressor (202), expansion valve (204), and flow diversion valve can be installed inside the casing of an outdoor unit installed outdoors of a building.

[0136] The outdoor heat exchanger (203) may be equipped with a plurality of heat exchange parts (1) arranged in the front-back direction and the up-down direction, and the inlet pipe and the discharge pipe of the outdoor heat exchanger (203) may be respectively connected to two heat exchange parts (1) located in different rows in the front-back direction. The heat exchanger (203) functions as a condenser, and the inlet pipe may be connected to a heat exchange part (1) located on the downwind side, and the discharge pipe may be connected to a heat exchange part (1) located on the upwind side.

[0137] The flow control unit (400) may be equipped with a processor, for example, a central processing unit (CPU), memory, an I / O interface, a communication interface, etc. The flow control unit (400) is operated by having the processor execute a predetermined program stored in the memory. The flow control unit (400) can control the amount of refrigerant introduced into the indoor heat exchanger (201), for example, by controlling the valve opening degree of the expansion valve (204) and the operation of the compressor (202), so that the superheat degree of the refrigerant discharged from the discharge pipe (4) of the indoor heat exchanger (201) is controlled to be equal to or higher than a predetermined value. The superheat degree means the degree to which the temperature of the refrigerant exceeds the saturation temperature. The superheat degree is controlled to be, for example, approximately 1 to 6 degrees.

[0138] Fig. 13a is a diagram showing the flow of refrigerant when the indoor heat exchanger (201) functions as an evaporator. Fig. 13b is a diagram showing the temperature change of air and refrigerant passing through the second-stage heat exchange units when the indoor heat exchanger (201) functions as an evaporator. Referring to Figs. 13a and 13b, the flow control unit (400) controls the flow rate of the refrigerant so that the refrigerant flowing along the heat transfer tubes (10) of the heat exchange unit (1H) is superheated (so that the refrigerant temperature exceeds the saturation temperature) in a predetermined region (hereinafter, superheat securing region (SH)) set at one end of the heat exchange unit (1H) to which the discharge pipe (4) is connected. The superheat securing region (SH) can be set over a predetermined length from one end of the heat exchange unit (1H) to which the discharge pipe (4) is connected toward the other end thereof.

[0139] Fig. 14a is a diagram showing the flow of refrigerant in a case where a heat exchanger, in which an introduction pipe is connected to a heat exchanger in the first row (upwind side) and a discharge pipe is connected to a heat exchanger in the second row (downwind side), functions as an evaporator. Fig. 14b is a diagram showing the temperature change of air and refrigerant passing through a heat exchanger, in a case where the heat exchanger illustrated in Fig. 14a functions as an evaporator. Referring to Figs. 13a, 13b, 14a, and 14b, it is explained that a relatively larger temperature difference between refrigerant and air can be secured near the discharge pipe (4) in the indoor heat exchanger (201) according to the present embodiment.

[0140] Referring to Fig. 13b, it can be seen that even if the refrigerant is superheated in the heat exchange unit (1H) on the windward side, a sufficient temperature difference is secured between the refrigerant to which the superheat is applied and the air on the windward side with a high temperature. Referring to Fig. 14a, the refrigerant is superheated in the heat exchange unit (second row, first stage heat exchange unit) on the windward side to which the discharge pipe is connected. The air passes through the heat exchange unit (second row, first stage heat exchange unit) on the windward side in a state where its temperature has been lowered by heat exchange with the heat exchange unit (first row, first stage heat exchange unit) on the windward side. Therefore, as illustrated in Fig. 14b, it may be difficult to secure a sufficient temperature difference between the refrigerant to which the superheat is applied in the heat exchange unit (second row, first stage heat exchange unit) on the windward side and the air.

[0141] The flow control unit (400) can control the amount of refrigerant introduced into the outdoor heat exchanger (203), for example, by controlling the operation of the compressor (202), so that the refrigerant discharged from the discharge pipe of the outdoor heat exchanger (203) is given a degree of subcooling (so that the refrigerant temperature falls below the saturation temperature).

[0142] As in the indoor heat exchanger (201) of this embodiment, since the discharge pipe (4) is connected to the heat exchange section (1H) on the windward side, the temperature difference between the refrigerant and the air near the discharge pipe (4) can be made as large as possible, and even if the refrigerant is greatly superheated near the discharge pipe (4), the temperature difference between the refrigerant and the air can be sufficiently secured to ensure heat exchange efficiency. In addition, since the introduction pipe (3) is also arranged on the windward side, the temperature difference near the introduction pipe (3) can also be secured.

[0143] Since the refrigerant flowing inside each of the heat transfer tubes (10) of the upstream heat exchanger (1G, 1I, 1J) does not merge or separate but flows into each of the heat transfer tubes (10) of the downstream heat exchanger (1H) through the connection (2), the temperature change of the refrigerant according to the flow direction of the refrigerant flowing inside each of the heat transfer tubes (10) becomes uniform. Accordingly, the unevenness of the position where the refrigerant exceeds the saturation temperature (the position where the superheat is applied) in each of the heat transfer tubes (10) can be reduced. In other words, the position where the refrigerant exceeds the saturation temperature in each of the heat transfer tubes (10) can become uniform. As a result, according to the heat exchanger (201), even if the superheat securing area (SH) is reduced, the refrigerant flowing in each of the heat transfer tubes (10) can be reliably provided with superheat. In addition, the heat exchange efficiency of the entire heat exchanger (1) can be secured by reducing the superheat securing area (SH) where the temperature difference with the air is small. Since the discharge pipe of the outdoor heat exchanger (203) functioning as a condenser is installed on the windward side, even if a degree of subcooling is applied to this discharge pipe, the temperature difference between the refrigerant and the air near this discharge pipe can be sufficiently secured.

[0144] Fig. 15a is a diagram showing the flow of refrigerant when the indoor heat exchanger (201) functions as a condenser. Fig. 15b is a diagram showing the temperature changes of air and refrigerant passing through the indoor heat exchanger (201) when the indoor heat exchanger (201) illustrated in Fig. 15a functions as a condenser. The case where the indoor heat exchanger (201) functions as a condenser, i.e., the case where the air conditioner (AC) is in heating operation, will be described with reference to Figs. 15a and 15b.

[0145] When functioning as a condenser, the flow direction of the refrigerant is reversed compared to when functioning as an evaporator, so the functions of the inlet and outlet pipes are reversed. Specifically, reference numeral 4 in FIGS. 15a and 15b denotes the inlet pipe, and reference numeral 3 denotes the outlet pipe.

[0146] If the discharge pipe (3) is positioned above the introduction pipe (4) in the vertical direction, the condensed liquid refrigerant must flow against gravity, which may cause partial stagnation of the refrigerant and reduce heat exchange efficiency. However, according to the indoor heat exchanger (201) of the present embodiment that functions as a condenser, the introduction pipe (4) is positioned above the discharge pipe (3) in the vertical direction. Since the condensed liquid refrigerant flows from top to bottom without going against gravity, stagnation of the refrigerant is unlikely to occur.

[0147] Since the flow of refrigerant within the refrigerant circuit (R) is reversed, the functions of the inlet and outlet pipes of the outdoor heat exchanger (203) are also reversed. Accordingly, the outlet pipe is placed on the downwind side, and the inlet pipe is placed on the upwind side.

[0148] The flow control unit (400) controls the amount of refrigerant introduced into the indoor heat exchanger (201) by controlling, for example, the valve opening degree of the expansion valve (204) or the operation of the compressor (202), thereby controlling the degree of subcooling of the refrigerant discharged from the discharge pipe (3) of the indoor heat exchanger (201) to a predetermined value or higher. The flow control unit (400) controls the flow rate of the refrigerant so that the degree of subcooling is imparted to the refrigerant flowing through each heat transfer tube (10) in a region (hereinafter, subcooling region (SC)) set at one end side of the heat exchange unit (1G) to which the discharge pipe (3) is connected (so that the temperature of the refrigerant falls below the saturation temperature). The degree of subcooling is set to, for example, 5 to 10 degrees.

[0149] Fig. 15b is a graph showing the temperature changes of the refrigerant and air passing through the first-stage heat exchanger (1I, 1G) of the heat exchanger (201) used as a condenser. Referring to Fig. 15b, since the discharge pipe (3) is installed on the windward side, a large temperature difference between the refrigerant and air in the discharge pipe (3) can be secured. In the outdoor heat exchanger (203) functioning as an evaporator during heating operation, there is little need to secure a degree of superheat near the discharge pipe. The flow control unit (400) can control the amount of refrigerant introduced into the outdoor heat exchanger (203), for example, by controlling the operation of the compressor (202), so as to prevent the refrigerant discharged from the discharge pipe of the outdoor heat exchanger (203) from being superheated (so that the refrigerant temperature does not exceed the saturation temperature). Even in this case where the indoor heat exchanger (201) functions as a condenser, since the discharge pipe (3) is installed on the windward side, the temperature difference between the refrigerant and the air near the discharge pipe (3) can be made as large as possible, and even in the case where a large degree of subcooling is applied to the refrigerant in the discharge pipe (3), the temperature difference between the refrigerant and the air can be sufficiently secured to ensure heat exchange efficiency.

[0150] Even in the case of an outdoor heat exchanger (203) functioning as an evaporator, since a discharge pipe that does not provide superheat is installed on the windward side, a sufficient temperature difference between the refrigerant and air can be secured throughout the refrigerant passage within the outdoor heat exchanger (203).

[0151] As described above, according to the air conditioner (AC) of the present embodiment, an indoor heat exchanger (201) and an outdoor heat exchanger (203) having different connection types of the discharge pipes and the introduction pipes are employed. That is, in the case of the indoor heat exchanger (201), the introduction pipe (3) is connected to one of a plurality of upwind heat exchangers, and the discharge pipe (4) is connected to another of a plurality of upwind heat exchangers. In addition, the introduction pipe and the discharge pipe of the outdoor heat exchanger (203) are respectively connected to two heat exchangers of different heat exchanger groups among a plurality of heat exchanger groups (14, 15) arranged in the air flow direction. According to the air conditioner (AC) as described above, the heat exchange efficiency of each heat exchanger (201)(203) can be secured in both heating operation and cooling operation, and as a result, the heat exchange efficiency of the entire refrigerant circuit can be maintained at a high level.

[0152] The number of rows of the heat exchanger group of the indoor heat exchanger (201) is not limited to two rows, and may be multiple. The heat exchanger group refers to multiple heat exchangers that belong to the same row in the front-rear direction of the heat exchanger (201) and are arranged in the vertical direction. Even when the heat exchanger group has three or more rows, the inlet and outlet pipes may be connected to two heat exchangers belonging to the same heat exchanger group, but this is not limited thereto. The inlet and outlet pipes may be connected to a heat exchanger group arranged on the windward side rather than a heat exchanger group arranged on the windward side. That is, the inlet and outlet pipes are not connected to a heat exchanger group arranged on the windward side. The inlet and outlet pipes may be connected to a heat exchanger group arranged on the windward side.

[0153] An air conditioner according to one aspect of the present disclosure comprises an indoor heat exchanger and an outdoor heat exchanger, wherein at least one of the indoor heat exchanger and the outdoor heat exchanger comprises: a plurality of heat exchange units, each heat exchange unit having a plurality of heat transfer tubes through which a refrigerant flows; a plurality of connecting portions connecting the plurality of heat exchange units in series to form a plurality of refrigerant passages; wherein each of the plurality of connecting portions connects two adjacent heat exchange units such that the flow directions of refrigerants flowing in each of the heat exchange units are opposite to each other, and at least one of the plurality of connecting portions connects two adjacent heat exchange units such that at least one of the plurality of refrigerant passages does not merge with another refrigerant passage. With this configuration, since at least one of the plurality of refrigerant passages is not merged or separated at the connecting portion and is connected from an upstream heat exchange unit to a downstream heat exchanger, a decrease in heat exchange efficiency of the heat exchanger due to a drift of the refrigerant can be reduced or prevented.

[0154] In one embodiment, at least one of the plurality of connecting portions may connect two adjacent heat exchangers such that not all of the plurality of refrigerant passages merge with each other. Accordingly, since not all of the plurality of refrigerant passages merge or diverge at the connecting portion and are connected from the upstream heat exchanger to the downstream heat exchanger, a decrease in heat exchange efficiency of the heat exchanger due to refrigerant drift can be further reduced or prevented. Furthermore, when a two-phase refrigerant (gas-liquid) flows in the heat exchanger, a decrease in heat exchange efficiency due to liquid accumulation at the connecting portion can be reduced or prevented.

[0155] As an example, the plurality of connecting portions may connect the plurality of heat exchange portions such that the lengths of the plurality of refrigerant passages are substantially the same. As a result, the pressure loss within the plurality of refrigerant passages can be made uniform.

[0156] As one embodiment, each of the plurality of connecting portions has a plurality of connecting passages connecting the heat transfer tubes of two adjacent heat exchange portions among the plurality of heat exchange portions, and the passage lengths of the plurality of connecting passages may be substantially the same. As a result, the pressure loss within the plurality of connecting passages may be made uniform.

[0157] As an example, the plurality of connecting channels may connect two heat transfer tubes of two adjacent heat exchange units among the plurality of heat exchange units, each of which is positioned at the same position in each heat exchange unit. As a result, the lengths of the plurality of refrigerant channels may be made substantially equal.

[0158] In one embodiment, each of the plurality of connecting portions has a plurality of connecting passages that connect heat transfer tubes of two adjacent heat exchange portions among the plurality of heat exchange portions, and the plurality of connecting passages can connect two heat transfer tubes positioned at symmetrical positions when connecting the heat transfer tubes of two adjacent heat exchange portions among the plurality of heat exchange portions. Accordingly, when an even number of connecting portions is provided, the sum of the lengths of the plurality of connecting passages arranged in series in each of the plurality of refrigerant passages can be the same, so that the pressure loss at the connecting portions can be uniform.

[0159] As an example, the plurality of heat exchange units may have the same number of heat transfer tubes.

[0160] As an example, the lengths of the plurality of heat transfer tubes of each of the plurality of heat exchange units may be substantially the same.

[0161] In one embodiment, the air conditioner may include at least one dummy heat transfer tube disposed between two adjacent heat exchange sections, through which no refrigerant flows. When the two heat exchange sections are disposed adjacent to each other, if there is a temperature difference between the upstream heat exchange section and the downstream heat exchange section, heat exchange may occur between the two opposing heat transfer tubes of the two heat exchange sections. Then, heat loss may increase, which may lower the heat exchange efficiency of the entire heat exchanger. Since the dummy heat transfer tube may impede the heat exchange between the two heat exchange sections, the heat exchange efficiency of the heat exchanger may be maintained.

[0162] In one embodiment, the plurality of heat exchange units may include a first heat exchange unit having a plurality of first heat transfer tubes arranged in parallel in a vertical direction and through which refrigerant flows in a first direction inside; a second heat exchange unit having a plurality of second heat transfer tubes arranged in parallel in the vertical direction and through which refrigerant flows in a second direction opposite to the first direction inside, and arranged to be adjacent to the first heat exchange unit in the vertical direction; The connecting unit may include an up-and-down switching connecting unit connecting downstream ends of the plurality of first heat transfer tubes to upstream ends of the plurality of second heat transfer tubes to introduce refrigerant flowing along the first heat transfer tubes into the second heat transfer tubes. The up-and-down switching connecting unit may include a plurality of up-and-down connecting passages that individually connect the plurality of first heat transfer tubes and the plurality of second heat transfer tubes.

[0163] As an example, the number of the plurality of first heat transfer tubes, the number of the plurality of second heat transfer tubes, and the number of the plurality of upper and lower connection channels are equal to each other, and the plurality of upper and lower connection channels can individually connect the plurality of first heat transfer tubes and the plurality of second heat transfer tubes.

[0164] Since the plurality of first heat transfer tubes of the first heat exchanger and the plurality of second heat transfer tubes of the second heat exchanger are connected in a one-to-one relationship through the plurality of upper and lower connection passages, the refrigerant flowing through the plurality of first heat transfer tubes does not merge or separate at the upper and lower connection passages, but flows to the plurality of corresponding second heat transfer tubes. Accordingly, the occurrence of drift in the plurality of refrigerant passages of the heat exchanger can be more reliably suppressed, and heat exchange efficiency can be maintained at a higher level.

[0165] As one embodiment, the plurality of upper and lower connecting passages connect the plurality of first heat transfer pipes and the plurality of second heat transfer pipes to each other, and the first heat transfer pipes and the second heat transfer pipes having the same upper and lower positions within the first heat exchange unit and the second heat exchange unit are connected to each other, and the passage lengths of the plurality of upper and lower connecting passages may be substantially the same.

[0166] As one embodiment, each of the plurality of upper and lower connecting passages may connect the first heat exchange unit and the plurality of first heat transfer pipes and the plurality of second heat transfer pipes of the second heat exchange unit, and may connect the first heat transfer pipe and the second heat transfer pipe that are positioned symmetrically in the upper and lower directions to each other.

[0167] In a plurality of refrigerant passages formed by individually connecting a plurality of first heat transfer tubes and a plurality of second heat transfer tubes through upper and lower connection passages, if the lengths of each passage are different, a difference in pressure loss may occur in the plurality of refrigerant passages, which may cause refrigerant drift. The plurality of upper and lower connection passages connect the first and second heat transfer tubes that are arranged in the same positions in the first and second heat exchange units, thereby making the passage lengths of the plurality of refrigerant passages uniform, thereby reducing refrigerant drift. In addition, if the passage lengths of the plurality of upper and lower connection passages are substantially the same, the lengths of the plurality of refrigerant passages formed by connecting the first and second heat transfer tubes through the upper and lower connection passages can be substantially the same, thereby reducing the difference in pressure loss in the plurality of refrigerant passages, and reducing refrigerant drift.

[0168] In one embodiment, the plurality of heat exchange units may include a third heat exchange unit having a plurality of third heat transfer tubes arranged in parallel in the vertical direction and through which refrigerant flows in the first direction, which is a direction opposite to the second direction, and arranged horizontally adjacent to the second heat exchange unit. The connection unit may include a horizontal conversion connection unit connecting a downstream end of the second heat transfer tube and an upstream end of the third heat transfer tube to introduce the refrigerant flowing along the second heat transfer tube into the third heat transfer tube. The horizontal conversion connection unit may include a plurality of horizontal connection passages that individually connect the plurality of second heat transfer tubes and the plurality of third heat transfer tubes.

[0169] Accordingly, since the plurality of second heat transfer tubes of the second heat exchange unit and the plurality of third heat transfer tubes of the third heat exchange unit are individually connected by the horizontal connecting passage, the refrigerant flowing through the plurality of second heat transfer tubes of the second heat exchange unit does not merge or re-divide at the horizontal conversion connecting section, but flows to the corresponding third heat transfer tubes, respectively. Accordingly, the gas-liquid two-phase refrigerant can be evenly distributed to the plurality of third heat transfer tubes of the third heat exchange unit, thereby maintaining the heat exchange efficiency of the heat exchanger.

[0170] When multiple heat exchange units are used in an evaporator, the vapor temperature decreases according to the pressure loss when the refrigerant flows along the heat transfer tube, so the temperature of the two-phase gas-liquid refrigerant introduced into the heat transfer tube gradually decreases as it flows downstream. In one embodiment, the multiple heat exchange units function as an evaporator, and the first heat exchange unit and the second heat exchange unit may be arranged on the upwind side, and the third heat exchange unit may be arranged on the downwind side. This can increase the temperature difference between the refrigerant and the air, thereby improving the heat exchange efficiency.

[0171] The above plurality of heat exchange units function as condensers, and the first heat exchange unit and the second heat exchange unit may be arranged on the downwind side, and the third heat exchange unit may be arranged on the upwind side.

[0172] In one embodiment, the plurality of heat exchange units may include a leeward heat exchange unit group including a plurality of leeward heat exchange units arranged in a direction perpendicular to the air flow direction and the plurality of refrigerant passages; and a leeward heat exchange unit group including a plurality of upwind heat exchange units arranged in a direction perpendicular to the air flow direction and the plurality of refrigerant passages and disposed on the upwind side relative to the leeward heat exchange unit group. The indoor heat exchanger may include an introduction pipe connected to one of the plurality of upwind heat exchange units and introducing refrigerant into the plurality of refrigerant passages; and a discharge pipe connected to another of the plurality of upwind heat exchange units and discharging refrigerant from the plurality of refrigerant passages.

[0173] With this configuration, since the discharge pipe is connected to the heat exchanger group on the windward side, the temperature difference between the refrigerant and the air near the discharge pipe can be made large, and even when the refrigerant is greatly superheated at the discharge pipe, the temperature difference between the refrigerant and the air can be sufficiently secured to ensure heat exchange efficiency. Even during slow operation, which accounts for most of the air conditioning operation time (for example, when the indoor temperature is close to the set temperature and the temperature difference between the refrigerant and the air inside the indoor heat exchanger is small), the temperature difference between the refrigerant and the air can be secured as large as possible to ensure heat exchange efficiency. Therefore, the cooling and heating efficiency of the air conditioner can be significantly improved. In addition, since both the discharge pipe and the introduction pipe are arranged on the windward side, even when the flow direction of the refrigerant is reversed and the operation is switched between the evaporator and the condenser (for example, when switching the operation of an air conditioner from cooling operation to heating operation or vice versa), the temperature difference between the refrigerant and the air near the discharge pipe can be maintained large, making the indoor heat exchanger suitable for use as an indoor unit.

[0174] In one embodiment, the plurality of heat exchange units may include a plurality of heat exchange units each arranged in a direction perpendicular to the air flow direction and the plurality of refrigerant passages, and may include a plurality of heat exchange unit groups arranged in the air flow direction. The outdoor heat exchanger may include an introduction pipe connected to a heat exchange unit belonging to one of the plurality of heat exchange unit groups and introducing refrigerant into the plurality of refrigerant passages; and a discharge pipe connected to a heat exchange unit belonging to another of the plurality of heat exchange unit groups and discharging refrigerant from the plurality of refrigerant passages.

[0175] The technical effects to be achieved in this document are not limited to the technical effects mentioned above, and other technical effects not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present disclosure pertains from the description of this document.

[0176] As described above, although the air conditioner of the present disclosure has been described by limited embodiments and drawings, the present disclosure is not limited to the above embodiments, and various modifications are possible without departing from the spirit thereof.

Claims

1. An air conditioner having an indoor heat exchanger (201) and an outdoor heat exchanger (203), wherein at least one of the indoor heat exchanger (201) and the outdoor heat exchanger (203) is A plurality of heat exchange units (1) each having a plurality of heat transfer tubes (10) through which refrigerant flows; It has a plurality of connecting parts (2) that connect the plurality of heat exchange parts in series to form a plurality of refrigerant passages, Each of the above plurality of connecting parts connects two adjacent heat exchange parts so that the flow direction of the refrigerant flowing in each of them is opposite to each other, An air conditioner in which at least one of the plurality of connecting portions connects two adjacent heat exchange portions such that at least one of the plurality of refrigerant passages does not join with another refrigerant passage.

2. In paragraph 1, An air conditioner in which at least one of the plurality of connecting portions connects two adjacent heat exchange portions such that not all of the plurality of refrigerant passages join with each other.

3. In paragraph 1 or 2, An air conditioner in which the plurality of connecting parts connect the plurality of heat exchange parts so that the lengths of the plurality of refrigerant passages are almost the same.

4. In any one of paragraphs 1 to 3, Each of the above plurality of connecting parts has a plurality of connecting passages (20) that connect the heat transfer tubes of two adjacent heat exchange parts among the above plurality of heat exchange parts. An air conditioner in which the lengths of the plurality of connecting euros are almost the same.

5. In paragraph 4, An air conditioner in which the above plurality of connecting paths connect the heat transfer tubes of two adjacent heat exchange units among the above plurality of heat exchange units, and the two heat transfer tubes in the same position in each heat exchange unit are connected to each other.

6. In any one of paragraphs 1 to 3, Each of the above plurality of connecting parts has a plurality of connecting passages (20) that connect the heat transfer tubes of two adjacent heat exchange parts among the above plurality of heat exchange parts. An air conditioner in which the above plurality of connecting paths connect the heat transfer tubes of two adjacent heat exchange units among the above plurality of heat exchange units, and the two heat transfer tubes are positioned symmetrically to each other.

7. In any one of paragraphs 1 to 6, The above plurality of heat exchangers have the same number of heat transfer tubes, An air conditioner in which the lengths of the plurality of heat transfer tubes of each of the plurality of heat exchange units are almost the same.

8. In any one of paragraphs 1 to 7, An air conditioner comprising at least one dummy heat transfer tube (6) disposed between two adjacent heat exchange sections and through which no refrigerant flows.

9. In paragraph 1, The above plurality of heat exchangers are: A first heat exchanger having a plurality of first heat transfer tubes arranged in a vertical direction and through which refrigerant flows in a first direction; A second heat exchange unit is provided with a plurality of second heat transfer tubes arranged in parallel in the vertical direction and through which refrigerant flows in a second direction opposite to the first direction along the inside, and is arranged adjacent to the first heat exchange unit in the vertical direction; The above connection part is, It has an upper and lower switching connection (2X) that connects the downstream end of the plurality of first heat transfer tubes and the upstream end of the plurality of second heat transfer tubes to introduce the refrigerant flowing along the first heat transfer tubes into the second heat transfer tubes; An air conditioner having a plurality of upper and lower connecting passages (20X) that individually connect the plurality of first heating tubes and the plurality of second heating tubes, wherein the upper and lower switching connection portion is provided.

10. In paragraph 9, The number of the plurality of first heating tubes, the number of the plurality of second heating tubes, and the number of the plurality of upper and lower connecting passages are equal to each other, An air conditioner in which the plurality of upper and lower connecting passages individually connect the plurality of first heating tubes and the plurality of second heating tubes.

11. In paragraph 10, The plurality of upper and lower connecting passages connect the plurality of first heat transfer pipes and the plurality of second heat transfer pipes to each other, and connect the first heat transfer pipes and the second heat transfer pipes that are located in the same upper and lower direction within the first heat exchange unit and the second heat exchange unit. An air conditioner in which the lengths of the plurality of upper and lower connecting passages are almost the same.

12. In paragraph 10, An air conditioner in which each of the plurality of upper and lower connecting passages connects the first heat exchange unit and the plurality of first heat transfer pipes and the plurality of second heat transfer pipes of the second heat exchange unit, and the first heat transfer pipes and the second heat transfer pipes are positioned symmetrically in the upper and lower directions to each other.

13. In any one of paragraphs 10 to 12, The above plurality of heat exchangers are: A third heat exchange unit having a plurality of third heat transfer tubes arranged in parallel in the vertical direction and through which refrigerant flows in the first direction, which is opposite to the second direction, and arranged horizontally adjacent to the second heat exchange unit; The above connection part is, It has a horizontal conversion connection (2Y) that connects the downstream end of the second heat pipe and the upstream end of the third heat pipe to introduce the refrigerant flowing along the second heat pipe into the third heat pipe; An air conditioner having a plurality of horizontal connection paths (20Y) that individually connect the plurality of second heating tubes and the plurality of third heating tubes, wherein the horizontal switching connection part is provided.

14. In any one of paragraphs 1 to 13, The above plurality of heat exchangers are: A leeward heat exchanger group (14) including a plurality of leeward heat exchangers (1I, 1J) arranged in a direction perpendicular to the air flow direction and the plurality of refrigerant passages; and It includes a plurality of upwind heat exchangers (1G, 1H) arranged in a direction perpendicular to the air flow direction and the plurality of refrigerant passages, and a group of upwind heat exchangers (15) arranged on the upwind side relative to the group of downwind heat exchangers; The above indoor heat exchanger (201) is An introduction pipe (3) connected to one of the plurality of windward side heat exchangers and introducing refrigerant into the plurality of refrigerant passages; An air conditioner including a discharge pipe (4) connected to another one of the plurality of windward side heat exchangers and discharging refrigerant from the plurality of refrigerant passages.

15. In paragraph 14, The plurality of heat exchange units each include a plurality of heat exchange units arranged in a direction perpendicular to the air flow direction and the plurality of refrigerant passages, and include a plurality of heat exchange unit groups (14, 15) arranged in the air flow direction. The above outdoor heat exchanger is, An introduction pipe connected to a heat exchanger belonging to one of the plurality of heat exchanger groups and introducing refrigerant into the plurality of refrigerant passages; An air conditioner including a discharge pipe connected to a heat exchanger belonging to another heat exchanger group among the plurality of heat exchanger groups and discharging refrigerant from the plurality of refrigerant passages.

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