Heat exchanger, air conditioner having same and manufacturing method of heat exchange

Abstract

A heat exchanger, a manufacturing method thereof, and an air conditioner having same are provided. The heat exchanger comprises: a tube through which a refrigerant can flow; and a plurality of heat exchange fins coupled to the tube so as to be in contact with the outer surface of the tube, wherein the tube and the heat exchange fins include an aluminum alloy, and the tube includes a zinc diffusion layer.

Description

Heat exchanger, air conditioner including same, and method for manufacturing heat exchanger

[0001] The present disclosure relates to a heat exchanger, an air conditioner including the same, and a method for manufacturing the heat exchanger.

[0002] An air conditioner is a device that performs functions such as air purification, ventilation, humidity control, cooling or heating in an air-conditioned space, and means a device equipped with at least one of these functions.

[0003] A heat exchanger is a component of a heat exchange cycle. It functions as a condenser or evaporator, allowing heat exchange between the refrigerant flowing within it and an external fluid. Depending on their shape, these heat exchangers are broadly categorized into fin-and-tube and microchannel types.

[0004] The above fin-and-tube type heat exchanger includes a plurality of fins and a tube of a circular or similar shape penetrating the fins, and the above microchannel type heat exchanger includes a plurality of flat tubes through which a refrigerant flows and fins provided between the plurality of flat tubes.

[0005] And, in the above fin-and-tube type heat exchanger and the above microchannel type heat exchanger, both the refrigerant flowing inside the tube or flat tube and the external fluid exchange heat. The fins serve to increase the heat exchange area between the refrigerant flowing inside the tube or flat tube and the external fluid.

[0006] Copper, known for its excellent corrosion resistance and weldability, was previously the primary material used for these tubes. However, its high price reduced product competitiveness, leading to the consideration of aluminum as a substitute. Aluminum offers a higher price competitiveness than copper. Furthermore, its excellent processability allows for the processing of various pipe shapes through extrusion and drawing processes. However, aluminum is susceptible to corrosion.

[0007] One aspect of the present disclosure provides a heat exchanger having improved corrosion resistance, an air conditioner including the same, and a method for manufacturing the heat exchanger.

[0008] One aspect of the present disclosure provides a heat exchanger having improved corrosion resistance by inducing general corrosion rather than pitting corrosion of a tube in a corrosive environment, an air conditioner including the same, and a method for manufacturing the heat exchanger.

[0009] The technical problems to be achieved in this document are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0010] A heat exchanger according to one embodiment of the present disclosure may include a tube through which a refrigerant can flow, and a plurality of heat exchange fins coupled to the tube so as to contact an outer surface of the tube. The tube and the heat exchange fins may comprise an aluminum alloy. The tube may include a zinc diffusion layer.

[0011] A method for manufacturing a heat exchanger according to one embodiment of the present disclosure may include manufacturing a heat exchange pipe by extruding an aluminum alloy. The method for manufacturing the heat exchanger may further include forming a zinc coating layer on the outer surface of the heat exchange pipe by zinc thermal spraying. The method for manufacturing the heat exchanger may further include forming a zinc diffusion layer on the heat exchange pipe by heat treating the heat exchange pipe on which the zinc coating layer has been formed.

[0012] According to the invention of the present invention, a heat exchanger having improved corrosion resistance can be provided by causing general corrosion rather than pitting corrosion through surface treatment.

[0013] According to the invention, a heat exchanger with improved corrosion resistance can be provided by inducing sacrificial corrosion of zinc to protect the base material of the tube from corrosion.

[0014] The effects that can be obtained from the present disclosure are not limited to the effects mentioned above, and other effects that are not mentioned can be clearly understood by a person having ordinary skill in the art to which the present disclosure belongs from the description below.

[0015] FIG. 1 is a perspective view of a heat exchanger according to one embodiment of the present disclosure.

[0016] FIG. 2 is a cross-sectional view of a tube having a zinc diffusion layer formed on the outer surface according to one embodiment of the present disclosure.

[0017] FIG. 3 is a cross-sectional view of a heat exchange pipe having a zinc coating layer formed on the outer surface according to one embodiment of the present disclosure.

[0018] FIG. 4 is a graph showing the results of measuring the zinc content according to depth from the outer surface of a tube according to one embodiment of the present disclosure using an Electron Probe Micro Analyzer (EPMA).

[0019] Figure 5 is a graph comparing the CASS evaluation (copper accelerated acetic acid salt spray test) leakage days according to the material of the heat exchanger.

[0020] Figure 6 is a graph comparing the maximum corrosion depth evaluated by CASS according to the zinc spray amount of pipe specification 4.76*0.7t pipe.

[0021] Figure 7 is a graph comparing the maximum corrosion depth evaluated by CASS according to the zinc spray amount of a pipe specification 7.00*1.0t pipe.

[0022] FIG. 8 is a drawing illustrating a configuration related to the flow of refrigerant in an air conditioner according to one embodiment of the present disclosure.

[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 encompass various modifications, equivalents, or alternatives 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 stand-alone air conditioner, and 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 indoor units 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 pipe in the order of a compressor, an outdoor heat exchanger, an expansion device, and an indoor heat exchanger, or in the order of a compressor, an indoor heat exchanger, an expansion device, and an outdoor heat exchanger.

[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 simultaneously 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 switching valve, described below, and then discharged to circulate to the outdoor unit.

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

[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] Hereinafter, embodiments according to the present invention will be described in detail with reference to the attached drawings.

[0085] FIG. 1 is a perspective view of a heat exchanger according to one embodiment of the present disclosure.

[0086] Referring to FIG. 1, a heat exchanger (1) according to one embodiment of the present disclosure may include a tube (10) through which a refrigerant can flow; and a plurality of heat exchange fins (11) coupled to the tube (10) so as to contact the outer surface of the tube (10).

[0087] The tube (10) and heat exchange fins (11) may comprise an aluminum alloy. The aluminum alloy may be A3003. Aluminum alloy materials can be highly price competitive compared to copper materials. Furthermore, due to their excellent processability, they can be processed into various pipe shapes through extrusion / drawing processes.

[0088] However, aluminum is susceptible to corrosion, and when applied to a heat exchanger, pitting corrosion may cause holes to form in the tube, resulting in refrigerant leakage. Pitting corrosion refers to local corrosion that creates holes or pits on the metal surface. If pitting corrosion occurs, there is a concern that the durability of the heat exchanger (1) may be reduced, and therefore it is desirable to minimize such corrosion. In the present disclosure, a zinc diffusion layer (17) is formed on the surface of an aluminum tube (10) to improve durability.

[0089] The tube (10) may include a zinc diffusion layer (17). Fig. 2 is a cross-sectional view of a tube (10) having a zinc diffusion layer (17) formed on the outer surface according to an embodiment of the present disclosure. Fig. 2 is a cross-sectional view taken along line A-A' of the tube (10) of Fig. 1. The central dotted line of Fig. 2 is an imaginary line indicating the center of the tube. Fig. 4 is a graph showing the results of measuring the zinc content according to the depth from the outer surface of the tube (10) according to an embodiment of the present disclosure using an Electron Probe Micro Analyzer (EPMA). The x-axis of Fig. 4 represents the depth (μm) from the outer surface of the tube, and the y-axis represents the zinc (Zn) content in wt%. The zinc diffusion layer (17) may mean a depth range in which the zinc content formed from the outer surface of the tube (10) changes.

[0090] Referring to FIG. 2 and / or FIG. 4, the zinc diffusion layer (17) can be formed with a maximum depth (18) of 150 μm from the outer surface of the tube (10). The formation location of the maximum depth (18) of the zinc diffusion layer is not limited to the example shown in FIG. 2. By sacrificial corrosion of zinc included in the zinc diffusion layer (17), general corrosion rather than pitting corrosion can occur, thereby improving corrosion resistance.

[0091] The corrosion resistance of aluminum (A3003), copper (C1220), and aluminum (A3003) with a zinc diffusion layer (17) was compared through the copper accelerated acetic acid salt spray test (CASS). The CASS test was performed by spraying a solution containing 5% NaCl and CuCl2 at a pH of 3.1 to 3.3 at a rate of 1.0 to 2.0 ml / h for 24 hours. The CASS test is a corrosion acceleration test and is one of the methods for evaluating corrosion resistance.

[0092] Figure 5 is a graph comparing CASS assessment leakage days according to heat exchanger materials. The x-axis of Figure 5 represents the heat exchanger material, and the y-axis represents the date of leakage according to the CASS assessment results. The date of leakage refers to the specific point in time when the leakage occurred according to the CASS assessment results, i.e., the date the leakage was first discovered. Table 1 compares the CASS assessment leakage days according to the heat exchanger material.

[0093] Referring to FIG. 5 and / or Table 1, it can be confirmed that when the tube (10) material is a copper alloy (C1220), a hole is created due to pitting corrosion on the 15th day, resulting in leakage. In addition, when the tube (10) material is an aluminum alloy (A3003), it can be confirmed that leakage occurs on the 10th day. Through this, it can be seen that when the tube (10) material is an aluminum alloy (A3003), it is more susceptible to corrosion than when the tube (10) material is a copper alloy (C1220).

[0094] Referring to FIG. 5 and / or Table 1, in Examples 1 to 3 in which an aluminum alloy (A3003) including a zinc diffusion layer (17) was used as the tube (10) material, leakage occurred on the 23rd, 25th, and 36th days, respectively. Through this, it can be confirmed that when the tube (10) material is an aluminum alloy (A3003) including a zinc diffusion layer (17), the corrosion resistance is improved compared to when the tube (10) material is a copper alloy (C1220) or an aluminum alloy (A3003).

[0095] Classification CASS Evaluation Comparison Preliminary Comparison Example 1 (C1220) 15th day leakage Comparison Example 2 (A3003) 10th day leakage Example Example 1 (A3003 + zinc diffusion layer) 23rd day leakage Example 2 (A3003 + zinc diffusion layer) 25th day leakage Example 3 (A3003 + zinc diffusion layer) 36th day leakage

[0096] The present disclosure seeks to derive the optimal zinc spray amount and zinc diffusion layer (17) depth conditions for the best corrosion resistance. When the maximum depth (18) of the zinc diffusion layer from the outer surface of the tube (10) is 150 μm, corrosion resistance can be increased. When the zinc spray amount is 2 g / m per unit area of ​​the pipe 2 5g / m 2 In this case, corrosion resistance can be increased. Fig. 2 is a cross-sectional view of a tube (10) according to one embodiment of the present disclosure. The formation location of the maximum depth of the zinc diffusion layer (18) is not limited to the example shown in Fig. 2. The amount of zinc sprayed and the maximum depth of the zinc diffusion layer (18) are related. When the amount of zinc sprayed is 5 g / m per unit area of ​​the tube (10), 2 In the case below, the maximum depth (18) of the zinc diffusion layer can be formed within 150 ㎛ from the outer surface of the tube (10). The zinc spraying amount is 5 g / m 2 In case of excess, the maximum depth (18) of the zinc diffusion layer can be formed to exceed 150 μm from the outer surface of the tube (10).

[0097] The maximum corrosion depth was measured weekly for two aluminum pipes with different zinc spray doses and maximum zinc diffusion layer depths (18) using the CASS evaluation. This allowed us to determine the effects of zinc spray doses and maximum zinc diffusion layer depths (18) on corrosion resistance.

[0098] The CASS evaluation was performed by spraying a solution containing 5% NaCl and CuCl2 at a pH of 3.1 to 3.3 at a rate of 1.0 to 2.0 ml / h for 24 hours. First, the degree of initial corrosion in the first week of the CASS test was compared. In the first week of the CASS test, the zinc sprayed amount was 5 g / m2 per unit area of ​​the pipe. 2 The maximum corrosion depth toward the center of the pipe at 20 random locations on the overcoated pipe was measured to be 80 μm to 190 μm. In the first week of the CASS test, the zinc sprayed amount was 5 g / m per unit area of ​​the pipe. 2 The maximum corrosion depth toward the center of the pipe at 20 random locations on the pipe coated below was measured to be 50 μm to 170 μm. Since the maximum corrosion depth in the first week increased as the zinc spray amount increased, it can be confirmed that the corrosion resistance decreased. The corrosion resistance of aluminum materials with a zinc spray surface treatment is improved by the principle that pitting corrosion is suppressed and general corrosion characteristics are achieved due to the sacrificial corrosion of zinc diffused directly under the surface. However, if the zinc concentration is too high, corrosion resistance may actually decrease.

[0099] Fig. 6 is a graph comparing the maximum corrosion depth evaluated by CASS according to the zinc spraying amount of a 4.76*0.7t pipe with pipe specifications. That is, it is a graph comparing the maximum corrosion depth toward the center of a pipe with an outer diameter of 4.76 mm and a thickness of 0.7 mm. Fig. 7 is a graph comparing the maximum corrosion depth evaluated by CASS according to the zinc spraying amount of a 7.00*1.0t pipe with pipe specifications. That is, it is a graph comparing the maximum corrosion depth toward the center of a pipe with an outer diameter of 7.00 mm and a thickness of 1.0 mm. The x-axis of the graphs of Figs. 6 and 7 represents the CASS evaluation period by week, and the y-axis represents the maximum corrosion depth toward the center of the pipe in μm. In addition, when the zinc spraying amount is 5 g / m per unit area of ​​the pipe, 2 For pipes with excess coating, the zinc spray amount is circled at 5g / m2 per unit area of ​​the pipe. 2 For pipes applied below, a legend is indicated by a square.

[0100] Referring to Figures 6 and 7, the zinc spray amount is 5 g / m per unit area of ​​the pipe. 2 For pipes with excess coating, the zinc spray amount is 5g / m2 per unit area of ​​the pipe. 2 In the case of pipes coated with zinc below, the maximum corrosion depth was measured deeper in the first to fifth weeks of the CASS test. As the amount of zinc sprayed increased, the maximum corrosion depth in the first to fifth weeks increased, so the zinc sprayed amount was 5 g / m per unit area of ​​the pipe. 2 Excessive application of zinc can result in reduced corrosion resistance. Aluminum materials treated with zinc spraying exhibit improved corrosion resistance due to the sacrificial corrosion of zinc diffused directly beneath the surface, suppressing pitting corrosion and promoting general corrosion. However, excessive zinc concentration can actually reduce corrosion resistance.

[0101] A heat exchanger (1) according to one embodiment of the present disclosure may include a section in which the concentration of zinc included in a zinc diffusion layer (17) decreases from the outer surface of the tube (10) toward the center of the tube (10). Fig. 4 is a graph showing the results of measuring the zinc content according to the depth from the outer surface of the tube according to one embodiment of the present disclosure using an Electron Probe Micro Analyzer (EPMA). Referring to Fig. 4, it can be confirmed that the heat exchanger (1) according to one embodiment of the present disclosure includes a section in which the concentration of zinc included in a zinc diffusion layer (17) decreases from the outer surface of the tube (10) toward the center of the tube (10).

[0102] In a heat exchanger (1) according to one embodiment of the present disclosure, 90% or less of the zinc content can be distributed at a depth of 0 µm to 100 µm in the zinc diffusion layer (17). More than 0% and 10% or less of the zinc content can be distributed at a depth of 100 µm to 150 µm in the zinc diffusion layer (17). Since 90% or less of the zinc content is distributed at a depth of 0 µm to 100 µm in the zinc diffusion layer (17) corresponding directly below the outer surface of the tube (10), pitting corrosion is suppressed due to sacrificial corrosion of zinc present in the zinc diffusion layer (17) and general corrosion characteristics are achieved, thereby improving corrosion resistance.

[0103] Sacrificial corrosion refers to the process of corroding another metal to prevent corrosion. This can occur due to the inherent potential difference between the different metals. In this process, the metal with the lower potential accelerates corrosion, while the metal with the higher potential is protected from corrosion.

[0104] According to one embodiment of the present disclosure, the heat exchanger (1) may have 50% to 60% of the zinc content distributed at a depth of 0 μm to 50 μm in the zinc diffusion layer (17). According to one embodiment of the present disclosure, the heat exchanger (1) may have 30% to 40% of the zinc content distributed at a depth of 50 μm to 100 μm in the zinc diffusion layer (17). According to one embodiment of the present disclosure, the heat exchanger (1) may have more than 0% and less than 10% of the zinc content distributed at a depth of 100 μm to 150 μm in the zinc diffusion layer (17). Due to the distribution of zinc as described above, pitting corrosion is suppressed and general corrosion characteristics are achieved due to sacrificial corrosion of zinc present in the zinc diffusion layer (17), thereby improving corrosion resistance.

[0105] Fluid can flow and heat exchange can take place inside the heat exchange pipe (13). The heat exchange fin (11) can increase the heat transfer area and thus improve the heat exchange efficiency. Fig. 1 is a perspective view of a heat exchanger (1) according to one embodiment of the present disclosure. Referring to Fig. 1, in the heat exchanger (1), a tube (10) may include a plurality of heat exchange pipes (13) extending in one direction and coupled with a plurality of heat exchange fins (11). A zinc diffusion layer (17) may be formed on the plurality of heat exchange pipes (13).

[0106] A bending pipe (14) is bent and extended from the ends of a plurality of heat exchange pipes (13) and can connect a plurality of heat exchange pipes (13). The tube (10) may further include a plurality of bending pipes (14). A zinc diffusion layer (17) may be formed on the plurality of bending pipes (14).

[0107] The inlet pipe (15) can supply refrigerant to a plurality of heat exchange pipes (13). The tube (10) may further include an inlet pipe (15) connected to one of the plurality of heat exchange pipes (13) to supply refrigerant to the plurality of heat exchange pipes (13). A zinc diffusion layer (17) may be formed in the inlet pipe (15).

[0108] An outlet pipe (16) can guide the discharged refrigerant. The tube (10) may further include an outlet pipe (16) connected to another one of the plurality of heat exchange pipes (13) to guide the refrigerant discharged from the plurality of heat exchange pipes (13). A zinc diffusion layer (17) may be formed on the outlet pipe (16).

[0109] In the heat exchanger (1), the zinc diffusion layer (17) may be formed on the entire outer surface of the tube (10), rather than only on a portion of the outer surface of the tube (10). As the zinc diffusion layer (17) is formed on the entire outer surface of the tube (10), local pitting corrosion of the tube (10) can be suppressed.

[0110] Such heat exchangers (1) can be applied in various forms within the scope of heat transfer between high-temperature liquids and low-temperature liquids. For example, the heat exchangers (1) can be applied in various fields such as waste heat recovery, cooling of high-temperature fluids, heating of low-temperature fluids, condensation of steam, and evaporation of low-temperature fluids.

[0111] The heat exchanger (1) can be applied to various devices including an air conditioner (200), a refrigerator, etc. Hereinafter, an application example of the heat exchanger (1) will be described using an air conditioner (200) as an example.

[0112] Figure 8 is a drawing showing a configuration related to the flow of refrigerant in an air conditioner (200) according to one embodiment.

[0113] Referring to the diagram shown in Fig. 8, the air conditioner (200) includes an outdoor unit (300) and an indoor unit (400), and a gas pipe (P1) that serves as a passage through which a gaseous refrigerant flows and a liquid pipe (P2) that serves as a passage through which a liquid refrigerant flows, connecting the outdoor unit (300) and the indoor unit (400). The gas pipe (P1) and the liquid pipe (P2) extend into the interior of the outdoor unit (300) and the indoor unit (400).

[0114] The outdoor unit (300) includes a compressor (310) that compresses refrigerant, an outdoor heat exchanger (320) that performs heat exchange between outdoor air and the refrigerant, and a four-way valve (330) that selectively guides the refrigerant compressed in the compressor (310) to either the outdoor heat exchanger (320) or the indoor unit (400) depending on the heating or cooling mode. In addition, the outdoor unit (300) includes an outdoor expansion valve (340) that decompresses the refrigerant guided to the outdoor heat exchanger (320) in the heating mode, and an accumulator (350) that prevents the liquid refrigerant that has not yet been evaporated from flowing into the compressor (310).

[0115] The compressor (310) can compress low-pressure gaseous refrigerant to high pressure by using the rotational power of a compressor motor (not shown) that rotates by receiving electric energy from an external power source.

[0116] The four-way valve (330) guides the refrigerant compressed in the compressor (310) to the outdoor heat exchanger (320) during cooling, and guides the refrigerant compressed in the compressor (310) to the indoor unit (400) during heating.

[0117] The outdoor heat exchanger (320) condenses the refrigerant compressed by the compressor (310) during cooling, and evaporates the refrigerant depressurized by the indoor unit (400) during heating. The outdoor heat exchanger (320) may be applied with the heat exchanger (1) according to the disclosed invention. In other words, it includes a tube (10) through which the refrigerant can flow, a heat exchange fin (11) bonded to the tube surface, and the tube (10) may include a zinc diffusion layer (17) formed with a maximum depth of 150 μm from the outer surface of the tube (10). Any description overlapping with the above will be omitted.

[0118] The outdoor expansion valve (340) not only reduces the pressure of the refrigerant in the heating mode, but can also control the amount of refrigerant supplied to the outdoor heat exchanger (320) so that sufficient heat exchange can occur in the outdoor heat exchanger (320). Specifically, the outdoor expansion valve (340) can reduce the pressure of the refrigerant by utilizing the throttling action of the refrigerant, in which the pressure of the refrigerant decreases without heat exchange with the outside when the refrigerant passes through a narrow passage.

[0119] The indoor unit (400) includes an indoor heat exchanger (410) that performs heat exchange between indoor air and refrigerant, and an indoor expansion valve (420) that depressurizes refrigerant supplied to the indoor heat exchanger (410) during cooling.

[0120] The indoor heat exchanger (410) can evaporate low-pressure liquid refrigerant during cooling and condense high-pressure gaseous refrigerant during heating. The heat exchanger (1) according to the disclosed invention can be applied to such an indoor heat exchanger (410), and for the sake of convenience of explanation, any description that overlaps with the above will be omitted.

[0121] The indoor expansion valve (420) can not only reduce the pressure of the refrigerant by using a throttling action, but also control the amount of refrigerant provided to the outdoor heat exchanger (320) so that sufficient heat exchange can occur in the indoor heat exchanger (410).

[0122] In the above, an example in which a heat exchanger (1) according to one embodiment is applied to an air conditioner (200) has been described.

[0123] Below, a method for manufacturing a heat exchanger (1) according to one embodiment of the present disclosure is described.

[0124] An aluminum alloy (A3003) ingot can be cast to create a billet. The billet can be heated to 450°C to 550°C and pressed to extrude it to 4 to 5 times the target outer diameter (Out Diameter) to manufacture a heat exchanger pipe.

[0125] Fig. 3 is a cross-sectional view of a heat exchange pipe having a zinc coating layer (19) formed on the outer surface according to one embodiment of the present disclosure. The central dotted line in Fig. 3 is an imaginary line indicating the center of the heat exchange pipe. The zinc coating layer (19) can be formed using a zinc thermal spraying method. The zinc thermal spraying can be performed by arc spraying. Zinc can be melted using a plasma welding arc and attached to the surface of the heat exchange pipe as shown in Fig. 3.

[0126] In the above zinc spraying, the amount of zinc sprayed per unit area of ​​the heat exchange pipe is 2 g / m 2 5g / m 2 As described above, referring to FIGS. 6 and 7, the zinc spraying amount per unit area of ​​the heat exchange pipe is 5 g / m 2 In case of excess, the zinc spray amount shall be 5g / m2 per unit area of ​​the heat exchange pipe. 2 In the case of heat exchanger pipes coated with zinc below, the maximum corrosion depth was deeper in the first to fifth weeks of the CASS test. As the amount of zinc sprayed increased, the maximum corrosion depth in the first to fifth weeks increased, so the zinc sprayed amount was 5 g / m per unit area of ​​the heat exchanger pipe. 2If the zinc concentration is excessive, it can be confirmed that the corrosion resistance is reduced. The corrosion resistance of aluminum materials with a zinc spray surface treatment is improved by the principle that pitting corrosion is suppressed and general corrosion characteristics are achieved due to the sacrificial corrosion of zinc diffused directly under the surface. However, it can be confirmed that the corrosion resistance is reduced if the zinc concentration is too high. The zinc spray amount is 2g / m 2 If it is less than 0.01, the sacrificial corrosion effect by zinc cannot be sufficiently obtained. Considering this, in the present disclosure, the zinc spraying amount is 2 g / m per unit area of ​​the heat exchange pipe. 2 5g / m 2 can be controlled by

[0127] The heat exchange pipe on which the zinc coating layer (19) is formed can be drawn to obtain the outer diameter of the target heat exchange pipe (13). The outer diameter (Out Diameter) of the target pipe can be 4.76 mm to 15.88 mm.

[0128] A heat exchange pipe (13) formed by drawing and forming a target outer diameter can be heat treated to form a zinc diffusion layer (17). The heat treatment can be performed at a temperature of 430°C to 510°C for 4 to 6 hours. Due to this heat treatment, zinc of the zinc coating layer (19) can diffuse toward the center of the heat exchange pipe (13), thereby forming a zinc diffusion layer (17). Fig. 2 is a cross-sectional view of a tube (10) having a zinc diffusion layer (17) formed on the outer surface according to one embodiment of the present disclosure. At this time, the specific shape of the zinc diffusion layer (17) is not limited to Fig. 2.

[0129] Less than 90% of the zinc sprayed amount can be distributed at a depth of 0 ㎛ to 100 ㎛ of the zinc diffusion layer (17). More than 0% and less than 10% of the zinc sprayed amount can be distributed at a depth of 100 ㎛ to 150 ㎛ of the zinc diffusion layer (17). Since less than 90% of the zinc sprayed amount is distributed at a depth of 0 ㎛ to 100 ㎛ in the zinc diffusion layer (17) corresponding directly below the outer surface of the heat exchange pipe (13), pitting corrosion is suppressed due to sacrificial corrosion of zinc present in the zinc diffusion layer (17) and general corrosion characteristics are achieved, thereby improving corrosion resistance.

[0130] 50% to 60% of the zinc sprayed amount can be distributed at a depth of 0 ㎛ to 50 ㎛ of the zinc diffusion layer. 30% to 40% of the zinc sprayed amount can be distributed at a depth of 50 ㎛ to 100 ㎛ of the zinc diffusion layer. More than 0% and less than 10% of the zinc sprayed amount can be distributed at a depth of 100 ㎛ to 150 ㎛ of the zinc diffusion layer. According to the distribution of zinc as described above, due to the sacrificial corrosion of zinc present in the zinc diffusion layer (17), pitting corrosion is suppressed and general corrosion characteristics are achieved, thereby improving corrosion resistance.

[0131] A heat exchanger (1) according to one embodiment of the present disclosure comprises a tube (10) through which refrigerant can flow and a plurality of heat exchange fins (11) coupled to the tube (10) so as to contact the outer surface of the tube (10). The tube (10) and the heat exchange fins (11) comprise an aluminum alloy. The tube (10) comprises a zinc diffusion layer (17).

[0132] The above zinc diffusion layer (17) can be formed with a maximum depth of 150 μm from the outer surface of the tube (10).

[0133] The concentration of zinc contained in the zinc diffusion layer (17) may include a section that decreases from the outer surface of the tube (10) toward the center of the tube (10).

[0134] In the above zinc diffusion layer (17), 90% or less of the zinc content may be distributed at a depth of 0 µm to 100 µm, and more than 0% and less than 10% of the zinc content may be distributed at a depth of 100 µm to 150 µm.

[0135] In the above zinc diffusion layer (17), 50% to 60% of the zinc content may be distributed at a depth of 0 μm to 50 μm, 30% to 40% of the zinc content may be distributed at a depth of 50 μm to 100 μm, and more than 0% and less than 10% of the zinc content may be distributed at a depth of 100 μm to 150 μm.

[0136] The above tube (10) may include a plurality of heat exchange pipes (13) extending in one direction and coupled with the plurality of heat exchange fins (11). The zinc diffusion layer (17) may be formed on the plurality of heat exchange pipes (13).

[0137] The above tube (10) may further include a plurality of bending pipes (14) that are bent and extended from the ends of the plurality of heat exchange pipes (13) in one direction. The zinc diffusion layer (17) may be formed on the plurality of bending pipes (14).

[0138] The above tube (10) may further include an inlet pipe (15) connected to one of the plurality of heat exchange pipes (13) to supply refrigerant to the plurality of heat exchange pipes (13) and an outlet pipe (16) connected to another of the plurality of heat exchange pipes (13) to guide refrigerant discharged from the plurality of heat exchange pipes (13). The zinc diffusion layer (17) may be formed in the inlet pipe (15) and the outlet pipe (16).

[0139] The above zinc diffusion layer (17) can be formed entirely on the outer surface of the tube (10).

[0140] An air conditioner (200) according to one embodiment may include the heat exchanger (1).

[0141] A method for manufacturing a heat exchanger (1) according to one embodiment may include manufacturing a heat exchange pipe (13) by extruding an aluminum alloy, forming a zinc coating layer (19) on the outer surface of the heat exchange pipe (13) by zinc thermal spraying, and heat-treating the heat exchange pipe (13) on which the zinc coating layer (19) is formed to form a zinc diffusion layer (17) on the heat exchange pipe (13).

[0142] In the above zinc spraying, the amount of zinc sprayed per unit area of ​​the heat exchange pipe (13) is 2 g / m 2 5g / m 2 It could be.

[0143] The above zinc spraying can be performed by arc spraying.

[0144] The manufacturing method of the above heat exchanger (1) may further include drawing the heat exchange pipe (13) after forming the zinc coating layer (19).

[0145] Forming the zinc diffusion layer (17) may include heat-treating the heat exchange pipe (13) on which the zinc coating layer (19) is formed at a temperature of 430°C to 510°C for 4 to 6 hours.

[0146] Less than 90% of the zinc sprayed amount may be distributed at a depth of 0 µm to 100 µm of the zinc diffusion layer (17), and more than 0% and less than 10% of the zinc sprayed amount may be distributed at a depth of 100 µm to 150 µm.

[0147] 50% to 60% of the zinc sprayed amount may be distributed at a depth of 0 µm to 50 µm of the zinc diffusion layer (17), 30% to 40% of the zinc sprayed amount may be distributed at a depth of 50 µm to 100 µm, and more than 0% and less than 10% of the zinc sprayed amount may be distributed at a depth of 100 µm to 150 µm.

[0148] The above illustrates and describes specific embodiments. However, the invention is not limited to the above-described embodiments, and those skilled in the art will readily appreciate that various modifications and implementations can be made without departing from the spirit and scope of the invention as set forth in the claims below.

[0149] (Explanation of symbols)

[0150] 1: Heat exchanger

[0151] 10: Tube

[0152] 11: Heat exchange fins

[0153] 12: Support plate

[0154] 13: Heat exchange pipe

[0155] 14: Bending pipe

[0156] 15: Inlet pipe

[0157] 16: Outlet pipe

[0158] 17: Zinc diffusion layer

[0159] 18: Maximum depth of zinc diffusion layer

[0160] 19: Zinc coating layer

[0161] 200: Air conditioner

[0162] 110: Compressor

[0163] 300: Outdoor unit

[0164] 310: Compressor

[0165] 320: Outdoor heat exchanger

[0166] 330: Four-way valve

[0167] 340: Outdoor expansion valve

[0168] 350: Accumulator

[0169] 400: Indoor unit

[0170] 410: Indoor heat exchanger

[0171] 420: Indoor expansion valve

[0172] P1: Gas pipe

[0173] P2: Liquid pipe

Claims

1. A tube through which the refrigerant can flow; and A plurality of heat exchange fins coupled to the tube so as to contact the outer surface of the tube; The above tube and the above heat exchange fin comprise an aluminum alloy, The above tube is a heat exchanger including a zinc diffusion layer.

2. In paragraph 1, A heat exchanger in which the zinc diffusion layer is formed to a maximum depth of 150 μm from the outer surface of the tube.

3. In paragraph 1, A heat exchanger comprising a section in which the concentration of zinc contained in the zinc diffusion layer decreases from the outer surface of the tube toward the center of the tube.

4. In paragraph 1, In the above zinc diffusion layer, less than 90% of the zinc content is distributed at a depth of 0 μm to 100 μm, A heat exchanger in which more than 0% and less than 10% of the zinc content is distributed at a depth of 100㎛ to 150㎛.

5. In paragraph 1, In the zinc diffusion layer, 50% to 60% of the zinc content is distributed at a depth of 0 μm to 50 μm, 30% to 40% of the zinc content is distributed at a depth of 50㎛ to 100㎛, A heat exchanger in which more than 0% and less than 10% of the zinc content is distributed at a depth of 100㎛ to 150㎛.

6. In paragraph 1, The above tube includes a plurality of heat exchange pipes extending in one direction and coupled with the plurality of heat exchange fins, A heat exchanger in which the zinc diffusion layer is formed on the plurality of heat exchange pipes.

7. In paragraph 6, The above tube further includes a plurality of bending pipes extending from the ends of the plurality of heat exchange pipes in the above one direction, A heat exchanger in which the zinc diffusion layer is formed on the plurality of bending pipes.

8. In paragraph 6, The tube further includes an inlet pipe connected to one of the plurality of heat exchange pipes to supply refrigerant to the plurality of heat exchange pipes, and an outlet pipe connected to another of the plurality of heat exchange pipes to guide refrigerant discharged from the plurality of heat exchange pipes. A heat exchanger in which the zinc diffusion layer is formed in the inlet pipe and the outlet pipe.

9. In paragraph 1, A heat exchanger in which the zinc diffusion layer is formed entirely on the outer surface of the tube.

10. An air conditioner comprising a heat exchanger according to one of claims 1 to 9.

11. Manufacturing a heat exchange pipe by extruding an aluminum alloy; A zinc coating layer is formed on the outer surface of the heat exchange pipe by zinc thermal spraying; A method for manufacturing a heat exchanger, comprising heat-treating the heat exchange pipe on which the zinc coating layer is formed to form a zinc diffusion layer on the heat exchange pipe.

12. In paragraph 11, In the above zinc spraying, the amount of zinc sprayed per unit area of ​​the heat exchange pipe is 2 g / m 2 5g / m 2 A method for manufacturing a heat exchanger.

13. In paragraph 11, A method for manufacturing a heat exchanger in which the above zinc spraying is performed by arc spraying.

14. In paragraph 11, A method for manufacturing a heat exchanger, further comprising drawing the heat exchange pipe after forming the zinc coating layer.

15. In paragraph 11, A method for manufacturing a heat exchanger, wherein forming the zinc diffusion layer comprises heat-treating the heat exchange pipe on which the zinc coating layer is formed at a temperature of 430°C to 510°C for 4 to 6 hours.

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