Air conditioner

Abstract

The utility model discloses an air conditioner, relates to the technical field of refrigeration, and aims to solve the problem that a heat exchanger in the air conditioner is poor in welding effect. The air conditioner comprises a shell, a heat exchanger, a refrigerant circulation assembly and a fan, the shell is provided with a mounting cavity, the heat exchanger is located in the mounting cavity, the refrigerant circulation assembly is communicated with the heat exchanger to form a refrigerant circulation loop, and the fan is used for driving air to flow through the heat exchanger; the collecting pipes comprise the first collecting pipe and the second collecting pipe which are arranged in a spaced mode, the communicating pipe is arranged between the first collecting pipe and the second collecting pipe, and the two ends of the communicating pipe are welded to the first collecting pipe and the second collecting pipe correspondingly so that the first collecting pipe and the second collecting pipe can both communicate with the communicating pipe. The multiple fins are arranged at intervals in the extending direction of the communicating pipe and connected with the communicating pipe. Wherein the collecting pipe is made of an aluminum alloy composite plate, the aluminum alloy composite plate comprises a base material layer and a composite layer arranged outside the base material layer, and the composite layer is solder of the base material layer.

Description

Technical Field

[0001] The present application relates to the technical field of refrigeration equipment, and in particular to an air conditioner. Background Art

[0002] The heat exchanger is an important component of the air conditioner and is widely used in heat exchange systems for heat exchange between the heat exchange medium and the outside air, or for heat exchange between two heat exchange media.

[0003] There are many different types of heat exchangers. Automotive heat exchangers usually use microchannel heat exchangers. After the various parts of the microchannel heat exchanger are assembled, a high-temperature brazing process needs to be performed in a brazing furnace.

[0004] However, during the brazing process, the solder often fails to fully fill the joint gap, resulting in poor connection strength of the welds between components, which affects the service life of the air conditioner. Utility Model Content

[0005] The present application provides an air conditioner, which is used to solve the problem of short service life of the air conditioner.

[0006] The embodiment of the present application provides an air conditioner, comprising a housing, a heat exchanger, a refrigerant circulation assembly and a fan. The housing has an installation cavity, the heat exchanger is located in the installation cavity, the refrigerant circulation assembly is connected to the heat exchanger to form a refrigerant circulation loop, and the fan is used to drive air to flow through the heat exchanger.

[0007] The heat exchanger includes a header, a connecting pipe and a plurality of fins, the header includes a first header and a second header arranged at intervals, the connecting pipe is arranged between the first header and the second header, and the two ends of the connecting pipe are respectively welded to the first header and the second header, so that the first header and the second header are both connected to the connecting pipe, and the plurality of fins are arranged at intervals along the extension direction of the connecting pipe and are all connected to the connecting pipe. Among them, the material of the header is an aluminum alloy composite plate, the aluminum alloy composite plate includes a substrate layer and a composite layer arranged outside the substrate layer, and the composite layer is the solder of the substrate layer.

[0008] In this way, since the composite layer and the substrate layer are stacked, when the heat exchanger is placed in a brazing furnace for brazing, the composite layer located on the outside of the substrate layer is converted into a molten state under the action of high temperature, and is gathered at the weld between the collecting pipe and the connecting pipe under the action of capillary phenomenon, so that the connection position between the collecting pipe and the connecting pipe has sufficient solder to be filled, which improves the solder filling effect between adjacent components and has better continuity of the weld during brazing, thereby improving the brazing strength and the structural strength of the heat exchanger.

[0009] In some embodiments of the present application, the thickness of the substrate layer accounts for 85-95% of the total thickness of the aluminum alloy composite plate, and the composite layer accounts for 5-15% of the total thickness of the aluminum alloy composite plate.

[0010] In some embodiments of the present application, the composite layer is a fourth series aluminum alloy.

[0011] In some embodiments of the present application, the connecting pipe and the plurality of fins are welded, and the connecting pipe is also made of an aluminum-gold composite plate.

[0012] In some embodiments of the present application, the first manifold includes a first manifold wall, a first manifold cavity is formed on the inner side of the first manifold wall, and a first port and a second port connected to the first manifold cavity are provided on the outer side of the first manifold wall. The second manifold includes a second manifold wall, a second manifold cavity is formed on the inner side of the second manifold wall, and a third port and a fourth port connected to the second manifold cavity are provided on the outer side of the second manifold wall. A channel is formed inside the connecting tube, and a first opening and a second opening connected to the channel are provided at both ends of the connecting tube, the first opening is connected to the second port, and the second opening is connected to the third port.

[0013] In some embodiments of the present application, there are multiple connecting tubes, and the multiple connecting tubes are arranged at intervals along the extension direction of the header, and there are multiple second ports and multiple third ports, and the multiple second ports are arranged at intervals along the extension direction of the first header, and the multiple third ports are arranged at intervals along the extension direction of the second header. The first openings of the multiple connecting tubes are connected one by one with the multiple second ports on the first header, and the second openings of the multiple connecting tubes are connected one by one with the multiple third ports on the second header.

[0014] In some embodiments of the present application, the first collecting pipe is provided with an assembly port connected to the first collecting cavity. The first collecting pipe also includes an end cover, which is arranged at the assembly port and is detachably connected to the first collecting pipe wall. The end cover is used to open or close the assembly port.

[0015] In some embodiments of the present application, the heat exchanger further includes an inlet pipe and an outlet pipe, one end of the inlet pipe is used to communicate with one side of the refrigerant circulation component, and the other end of the inlet pipe is connected to the first port. One end of the outlet pipe is connected to the other side of the refrigerant circulation component, and the other end of the inlet pipe is connected to the fourth port.

[0016] In some embodiments of the present application, the heat exchanger includes a first adapter seat provided between the inlet pipe and the first header, and a second adapter seat provided between the outlet pipe and the second header.

[0017] The embodiment of the present application also provides an air conditioner, which includes a shell, a heat exchanger, a refrigerant circulation component and a fan. The shell has an installation cavity, and the heat exchanger is located inside the installation cavity. The refrigerant circulation component is connected to the heat exchanger through a refrigerant pipeline, and the fan is used to drive air to flow through the heat exchanger. The heat exchanger includes a header, a connecting pipe and a plurality of fins, and the header includes a first header and a second header arranged at intervals. Both ends of the connecting pipe are respectively welded to the first header and the second header, so that the first header and the second header are connected to the connecting pipe, and the plurality of fins are arranged on the connecting pipe. Among them, the material of the header is an aluminum alloy composite plate, and the aluminum alloy composite plate includes a substrate layer and a composite layer arranged outside the substrate layer, and the composite layer is the solder of the substrate layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to provide a further understanding of the technical solution of the utility model and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the utility model and do not constitute a limitation on the technical solution of the utility model.

[0019] Figure 1 A structural block diagram of an air conditioner provided in an embodiment of the present application;

[0020] Figure 2 A structural block diagram of an air conditioner in a cooling mode provided by an embodiment of the present application;

[0021] Figure 3 A structural block diagram of an air conditioner in a heating mode provided by an embodiment of the present application;

[0022] Figure 4 One of the partial schematic diagrams of a microchannel heat exchanger provided in the related art;

[0023] Figure 5 The second partial schematic diagram of the microchannel heat exchanger provided in the related art;

[0024] Figure 6 One of the structural schematic diagrams of the microchannel heat exchanger provided in the embodiment of the present application;

[0025] Figure 7 A schematic diagram of the structure of the aluminum alloy composite plate provided in the embodiment of the present application;

[0026] Figure 8 A schematic diagram of the structure of a first manifold provided in an embodiment of the present application;

[0027] Fig. 9 A schematic diagram of the structure of a second manifold provided in an embodiment of the present application;

[0028] Fig.10 One of the structural schematic diagrams of the connecting pipe provided in the embodiment of the present application;

[0029] Fig.11 The second structural schematic diagram of the connecting pipe provided in the embodiment of the present application;

[0030] Fig.12 The third structural diagram of the connecting pipe provided in the embodiment of the present application;

[0031] Fig.13 This is the second structural schematic diagram of the microchannel heat exchanger provided in the embodiment of the present application.

[0032] Reference numerals:

[0033] Connecting pipe 31; channel 311; first opening 312; second opening 313; fin 32; manifold 33; first manifold 331; first manifold wall 3311; first manifold cavity 3312; first port 3313; second port 3314; assembly port 3315; end cover 3316; second manifold 332; second manifold wall 3321; second manifold cavity 3322; third port 3323; fourth port 3324; aluminum alloy composite plate 34; substrate layer 341; composite layer 342; inlet pipe 35; outlet pipe 36; first adapter seat 37; second adapter seat 38. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0035] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back...) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0036] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0037] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances. In addition, when describing a pipeline, the "connected" and "connection" used in this application have the meaning of conduction. The specific meaning needs to be understood in conjunction with the context.

[0038] In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0039] The present application embodiment provides an air conditioner, referring to Figure 1 , Figure 1 The structural block diagram of an air conditioner provided in an embodiment of the present application is shown. The air conditioner 100 may include a compressor 1, a four-way valve 2, an outdoor heat exchanger 3a and an indoor heat exchanger 3b. The four-way valve 2 has a first valve port 21, a second valve port 22, a third valve port 23 and a fourth valve port 24. The compressor 1 has an air inlet 101 and an air outlet 102. The air inlet 101 is connected to the first valve port 21, and the air outlet 102 is connected to the second valve port 22. One end of the outdoor heat exchanger 3a is connected to the third valve port 23. One end of the indoor heat exchanger 3b is connected to the fourth valve port 24, and the other end is connected to the other end of the outdoor heat exchanger 3a.

[0040] Both the indoor heat exchanger 3a and the outdoor heat exchanger 3b can be microchannel heat exchangers 3. The indoor heat exchanger 3a and the outdoor heat exchanger 3b can also be heat storage heat exchangers, direct contact heat exchangers, and partition heat exchangers. For the convenience of description, the indoor heat exchanger and the outdoor heat exchanger are described below using the microchannel heat exchanger 3 as an example.

[0041] The compressor 1 can compress the refrigerant into a high-temperature and high-pressure gaseous refrigerant, and can discharge the compressed gaseous refrigerant. The outdoor microchannel heat exchanger 3a and the indoor microchannel heat exchanger 3b can be used as a condenser or an evaporator. When the outdoor microchannel heat exchanger 3a or the indoor microchannel heat exchanger 3b is used as a condenser, the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 1 can be condensed into a high-pressure and medium-temperature liquid refrigerant, and the heat is released into the surrounding environment through the condensation process. When the outdoor microchannel heat exchanger 3a or the indoor microchannel heat exchanger 3b is used as an evaporator, the liquid refrigerant can be evaporated into a gaseous refrigerant by absorbing the heat of the surrounding environment, thereby achieving a refrigeration effect.

[0042] It is understood that when the air conditioner is in heating mode, the outdoor micro-channel heat exchanger 3a is used as an evaporator and the indoor micro-channel heat exchanger 3b is used as a condenser. When the air conditioner 100 is in cooling mode, the outdoor micro-channel heat exchanger 3a is used as a condenser and the indoor micro-channel heat exchanger 3b is used as an evaporator.

[0043] Continue to refer to Figure 1 It can be understood that the air conditioner 100 provided in the embodiment of the present application may also include an oil separator 4, a gas-liquid separator 5, an outdoor fan 6, an indoor fan 7, an outdoor expansion valve 8, an indoor expansion valve 9, an oil return pressure reducing pipe 10 and a plurality of stop valves 11.

[0044] Among them, the oil separator 4 is connected between the air outlet 102 of the compressor 1 and the second valve port 22 of the four-way valve 2, and is used to separate the lubricating oil mixed in the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 1, thereby ensuring the safe and efficient operation of the air-conditioning system.

[0045] The gas-liquid separator 5 is connected between the air inlet 101 of the compressor 1 and the first valve port 21 of the four-way valve 2. Its main function is to store part of the refrigerant in the air-conditioning system to prevent liquid hammer in the compressor 1 and excessive refrigerant from diluting the compressor oil.

[0046] The outdoor fan 6 is located at the outdoor microchannel heat exchanger 3a, and is used to accelerate the flow of air around the outdoor microchannel heat exchanger 3a, thereby improving the heat exchange efficiency of the outdoor microchannel heat exchanger 3a. The indoor fan 7 is located at the indoor microchannel heat exchanger 3b, and is used to accelerate the flow of air around the indoor microchannel heat exchanger 3b, thereby improving the heat exchange efficiency of the indoor microchannel heat exchanger 3b.

[0047] The outdoor expansion valve 8 and the indoor expansion valve 9 are both located between the indoor microchannel heat exchanger 3b and the outdoor microchannel heat exchanger 3a, wherein the outdoor expansion valve 8 is located on the side close to the outdoor microchannel heat exchanger 3a, and the indoor expansion valve 9 is located on the side close to the indoor microchannel heat exchanger 3b. The function of both is to throttle and reduce the pressure of the high-pressure and medium-temperature refrigerant after condensation by the condenser, so that it becomes a low-temperature and low-pressure refrigerant that is easy to evaporate, thereby achieving the purpose of improving the evaporation efficiency of the evaporator.

[0048] The oil return pressure reducing pipe 10 is connected between the oil separator 4 and the air inlet 101 of the compressor 1 , and is used to reduce the pressure of the high-pressure lubricating oil discharged from the compressor 1 to prevent the high-pressure lubricating oil from directly entering the compressor 1 and causing damage to the compressor 1 .

[0049] The plurality of stop valves 11 are respectively located between the outdoor expansion valve 8 and the indoor expansion valve 9 and between the indoor microchannel heat exchanger 3 b and the fourth valve port 24 .

[0050] Exemplarily, two stop valves 11 are provided between the outdoor expansion valve 8 and the indoor expansion valve 9, and a liquid pipe is connected between the two stop valves 11; two stop valves 11 are provided between the indoor microchannel heat exchanger 3b and the fourth valve port 24, and a gas pipe is connected between the two stop valves 11.

[0051] The conduction mode of the first valve port 21, the second valve port 22, the third valve port 23 and the fourth valve port 24 in the four-way valve 2 can be changed. By changing the conduction mode of the first valve port 21, the second valve port 22, the third valve port 23 and the fourth valve port 24 in the four-way valve 2, the functions of the outdoor microchannel heat exchanger 3a and the indoor microchannel heat exchanger 3b can be changed, and then the working mode of the air conditioner 100 can be changed.

[0052] The following is a further introduction to the conduction mode of the four-way valve and the flow direction of the refrigerant when the air conditioner is in different working modes, in conjunction with the accompanying drawings.

[0053] Reference Figure 2 , Figure 2 This is a structural block diagram of an air conditioner in cooling mode provided by an embodiment of the present application. When the air conditioner 100 is in cooling mode, first, the second valve port 22 of the four-way valve 2 is connected to the third valve port 23, and the first valve port 21 is connected to the fourth valve port 24. The low-temperature and low-pressure refrigerant is compressed by the compressor 1 to form a high-temperature and high-pressure superheated refrigerant gas, which is then discharged from the compressor 1. The high-temperature and high-pressure gaseous refrigerant discharged from the compressor 1 passes through the oil separator 4 to remove oil and then flows into the outdoor microchannel heat exchanger 3a through the four-way valve 2.

[0054] Next, the high-temperature and high-pressure gaseous refrigerant is condensed into high-pressure and medium-temperature liquid refrigerant in the outdoor microchannel heat exchanger 3a. At the same time, the outdoor fan 6 is running to accelerate the heat exchange between the refrigerant and the air around the outdoor microchannel heat exchanger 3a.

[0055] Then, the liquid refrigerant flowing out of the outdoor microchannel heat exchanger 3a flows through the outdoor expansion valve 8, the stop valve 11 and the indoor expansion valve 9 in sequence. After the two throttling and pressure reduction by the outdoor expansion valve 8 and the indoor expansion valve 9, the high-pressure and medium-temperature liquid refrigerant becomes a low-temperature and low-pressure gas-liquid two-phase mixed refrigerant.

[0056] Next, the low-temperature and low-pressure gas-liquid two-phase mixed refrigerant enters the indoor microchannel heat exchanger 3b, and is transformed into a low-temperature and low-pressure gaseous refrigerant after evaporation in the indoor microchannel heat exchanger 3b. At the same time, the operation of the indoor fan 7 can accelerate the heat exchange between the refrigerant and the air around the indoor microchannel heat exchanger 3b. As a result, the refrigerant absorbs indoor heat in the indoor microchannel heat exchanger 3b, thereby achieving the purpose of lowering the indoor temperature.

[0057] Finally, the refrigerant coming out of the indoor microchannel heat exchanger 3b passes through the stop valve 11, the four-way valve 2 and the gas-liquid separator 5 in sequence, and then flows into the air inlet 101 of the compressor 1, thus completing the entire refrigeration cycle.

[0058] Reference Figure 3 , Figure 3 This is a structural block diagram of an air conditioner in a heating mode provided by an embodiment of the present application. When the air conditioner 100 is in the heating mode, first, the second valve port 22 of the four-way valve 2 is connected to the fourth valve port 24, and the first valve port 21 is connected to the third valve port 23. The low-temperature and low-pressure refrigerant is compressed by the compressor 1 to form a high-temperature and high-pressure superheated refrigerant gas, which is then discharged from the compressor 1; the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 1 passes through the oil separator 4 to remove oil, and then flows into the indoor microchannel heat exchanger 3b through the four-way valve 2 and the stop valve 11.

[0059] Next, the high-temperature and high-pressure gaseous refrigerant exchanges heat with the indoor air in the indoor microchannel heat exchanger 3b and is condensed into a high-pressure and medium-temperature liquid refrigerant. The heat released by the refrigerant during the condensation process is sent into the room, thereby achieving the purpose of increasing the indoor temperature. At the same time, the indoor fan 7 is running to speed up the heat exchange speed between the indoor air and the refrigerant.

[0060] Then, the high-pressure and medium-temperature liquid refrigerant flowing out of the indoor microchannel heat exchanger 3b flows through the indoor expansion valve 9, the stop valve 11 and the outdoor expansion valve 8 in sequence. After two throttling and pressure reduction by the indoor expansion valve 9 and the outdoor expansion valve 8, the high-pressure and medium-temperature liquid refrigerant becomes a low-temperature and low-pressure gas-liquid two-phase mixed refrigerant. Then, the low-temperature and low-pressure gas-liquid two-phase mixed refrigerant enters the outdoor microchannel heat exchanger 3a, and becomes a low-temperature and low-pressure gas refrigerant after evaporation by the outdoor microchannel heat exchanger 3a. At the same time, the outdoor fan 6 is running, which can accelerate the heat exchange between the refrigerant and the air around the outdoor microchannel heat exchanger 3a.

[0061] Finally, the refrigerant coming out of the outdoor microchannel heat exchanger 3a passes through the four-way valve 2 and the gas-liquid separator 5 in sequence, and then flows into the air inlet 101 of the compressor 1, thus completing the entire heating cycle.

[0062] Compared with copper tube fin microchannel heat exchangers, aluminum insert microchannel heat exchangers have the potential to completely replace copper tube fin microchannel heat exchangers due to their higher heat transfer coefficient, lighter weight, and less refrigerant charge.

[0063] like Figure 4 As shown, Figure 4 One of the partial schematic diagrams of a microchannel heat exchanger provided in the related art is shown. Figure 5 A second partial schematic diagram of a microchannel heat exchanger provided in the related art is shown.

[0064] Combined with reference Figure 4 and Figure 5 The microchannel heat exchanger 3 generally includes a connecting pipe 31, fins 32 arranged on the outer surface of the connecting pipe 31, and headers 33 arranged at both ends of the connecting pipe 31. Refrigerant can flow through the connecting pipe 31, and the refrigerant can exchange heat with the external air through the fins 32. Since the connecting pipe 31, the fins 32 and the header 33 are generally connected together by brazing, and the solder often fails to fully fill the joint gap during the brazing process, the connection strength of the welds between the components will be poor, thereby affecting the overall service life of the microchannel heat exchanger and the air conditioner.

[0065] Based on this, in order to improve the filling effect of the welds between the components in the microchannel heat exchanger 3, thereby improving the welding strength of the microchannel heat exchanger 3 and the overall service life of the air conditioner 100. The embodiment of the present application provides a microchannel heat exchanger 3, and at least one of the outdoor microchannel heat exchanger 3a and the indoor microchannel heat exchanger 3b in the air conditioner 100 can use the microchannel heat exchanger 3. The microchannel heat exchanger 3 provided in the embodiment of the present application is further introduced below.

[0066] Figure 6 FIG. 1 shows one of the structural schematic diagrams of the microchannel heat exchanger 3 provided in the embodiment of the present application, see FIG. Figure 6 The microchannel heat exchanger 3 includes a header 33, a connecting pipe 31 and a plurality of fins 32. The header 33 includes a first header 331 and a first header 332 which are arranged at intervals. The connecting pipe 31 is arranged between the first header 331 and the first header 332, and the two ends of the connecting pipe 31 are respectively welded to the first header 331 and the first header 332, so that the first header 331 and the first header 332 are both connected to the connecting pipe 31. The plurality of fins 32 are arranged at intervals along the extending direction of the connecting pipe 31 and are all connected to the connecting pipe 31. In this way, the basic structure of the microchannel heat exchanger 3 is assembled to provide conditions for the subsequent brazing process.

[0067] It should be noted that, see Figure 7 , Figure 7 A schematic structural diagram of an aluminum alloy composite plate 34 provided in an embodiment of the present application is shown. The material of the collecting tube 33 is the aluminum alloy composite plate 34. The aluminum alloy composite plate 34 includes a substrate layer 341 and a composite layer 342 arranged outside the substrate layer 341. The composite layer 342 is the solder of the substrate layer 341.

[0068] It can be understood that since the composite layer 342 and the substrate layer 341 are stacked, when the microchannel heat exchanger 3 is placed in a brazing furnace for brazing, the composite layer 342 located on the outside of the substrate layer 341 is converted into a molten state under the action of high temperature, and is gathered at the weld between the collecting pipe 33 and the connecting pipe 31 under the action of capillary phenomenon, so that the connection position between the collecting pipe 33 and the connecting pipe 31 has sufficient solder to be filled, which improves the solder filling effect between adjacent components, and the continuity of the weld during brazing is better, thereby improving the brazing strength and the structural strength of the microchannel heat exchanger 3.

[0069] In some embodiments of the present application, the substrate layer 341 may be a magnesium-aluminum alloy, and the mass percentage of the magnesium content is between 0.2-0.4.

[0070] Table 1 shows the test results of the mass ratio of magnesium content and the flame welding effect, and Table 2 shows the test results of the mass ratio of magnesium content and the brazing effect. Referring to Table 1 and Table 2, it can be seen that the mass ratio of magnesium content has an important influence on both the flame welding effect and the brazing effect. The present application prepares samples and brazes with different concentration gradients of magnesium content in the substrate layer 341. The verification results of the sample plate after brazing show that when the mass ratio of magnesium content is greater than 0.4, the weld filling is discontinuous, there are partial depressions, and the connection strength after brazing is poor. When the mass ratio of magnesium content is less than 0.2, although the weld is continuous, there are obvious white flux residues on the outside of the weld, which can easily lead to pitting and perforation failure, and is not conducive to improving the connection strength of parts after brazing.

[0071] Table 1

[0072] Test groups Magnesium content Flame welding effect 1 0.8％ The weld is discontinuous and there is no flux residue on the outside of the weld 2 0.5％ The weld is continuous and there is no flux residue on the outside of the weld 3 0.2％ The weld is continuous, with slight flux residue on the outside of the weld 4 0.1％ The weld is continuous, and there is obvious flux residue on the outside of the weld

[0073] Table 2

[0074]

[0075]

[0076] Thus, during the brazing process, the molten flux will dissolve and flow, first removing the aluminum oxide film on the surface of the manifold 33, then floating on the surface of the dissolved composite layer 342 (i.e., solder), and flowing on the surface of the substrate layer 341 of the manifold 33 together with the dissolved solder, and gathering to the lower surface of the manifold 33 and the lower surface of the connecting weld under the action of gravity and capillary action. Since 0.2% to 0.4% magnesium has a hydrophobic property similar to that of the molten flux, when the substrate layer 341 is a magnesium-aluminum alloy and the mass proportion of the magnesium content is 0.2% to 0.4%, the fluidity of the molten flux flowing on the surface of the substrate layer 341 of the manifold 33 will increase, so that the excess molten flux can drip smoothly from the surface of the manifold 33, thereby helping to reduce the flux residue on the surface of the manifold 33 after brazing.

[0077] It is understandable that since the flux residues easily absorb water vapor and liquid condensed water in the surrounding environment, and under the influence of liquid condensed water and acidic gases in the atmosphere, the aluminum alloy parts at the flux residues will undergo galvanic reactions and produce pitting corrosion. The substrate layer 341 of the present application uses a magnesium-containing aluminum alloy with a magnesium content of 0.2%-0.4% by mass, and uses its hydrophobic properties to promote the separation of the flux residues from the surface of the manifold 33. In this way, on the one hand, the neatness of the product appearance is improved, and on the other hand, the pitting and perforation failure phenomenon caused by the flux residues at the connection position between the manifold 33 and the connecting tube 31 can be reduced, thereby also having the effect of enhancing the welding strength.

[0078] For example, the substrate layer can be made of 3005 or 3005MOD without changing the magnesium content, so as to reduce the flux residues at the weld between the collector and the connecting tube and on the collector without affecting the forming, processing and manufacturing of the collector and the subsequent core brazing process, thereby improving the appearance and corrosion resistance of the microchannel heat exchanger 3.

[0079] In some embodiments of the present application, the thickness of the substrate layer 341 accounts for 85-95% of the total thickness of the aluminum alloy composite plate 34 , and the composite layer 342 accounts for 5-15% of the total thickness of the aluminum alloy composite plate 34 .

[0080] It is understandable that when the thickness of the composite layer 342 is too small, that is, the amount of solder is small, the solder seam after brazing will be discontinuous due to the small amount of solder during the brazing process. When the thickness of the composite layer 342 is too large, that is, the amount of solder is large, on the one hand, the excess solder after brazing will form convexities or concave on the surface of the part after melting and cooling, and on the other hand, it also causes waste of materials.

[0081] Exemplarily, the composite layer 342 used as solder may be a fourth-series aluminum alloy, which enables rapid heat dissipation during welding, thereby avoiding problems such as deformation and cracking of welded parts.

[0082] In some embodiments of the present application, the connecting tube 31 and the multiple fins 32 are welded, and the material of the connecting tube 31 is also an aluminum alloy composite plate 34, so that during the brazing process, the weld filling effect between the connecting tube 31 and the multiple fins 32 is better, and the weld after brazing is continuous, thereby improving the connection strength of the internal components of the microchannel heat exchanger 3.

[0083] It should be noted that in order to ensure the brazing effect, after the connecting pipe 31, fins 32 and header 33 and other parts are assembled into the core of the microchannel heat exchanger 3, the brazing flux is sprayed before brazing, and the brazing is carried out in a nitrogen-protected continuous brazing furnace. The brazing flux component is potassium fluoroaluminate (K1~3AlF4~6nH2O), with a melting point of 562℃-572℃. When the temperature of the brazing furnace reaches 572℃, the brazing flux melts, and the melted brazing flux spreads on the surface of the parts, causing the alumina film to dissociate and dissolve. When the temperature of the brazing furnace reaches 577℃, the solder on the fins 32 and the header 33 begins to melt. Through capillary action, the molten solder expands through wetting to form welds at the joints between the fins 32 and the connecting pipe 31, and the header 33 and the connecting pipe 31.

[0084] Due to the very active chemical properties of aluminum, the surface of aluminum alloy parts easily reacts with oxygen at room temperature to form a dense, high-melting-point aluminum oxide film. The aluminum oxide generated at a high temperature above 300°C accumulates faster. The melting point of the aluminum oxide film is 2050°C, and the temperature of the brazing furnace is set at 550°C to 625°C. The presence of the aluminum oxide film will prevent the brazing of aluminum alloys. When brazing, the nitrogen-protected continuous brazing furnace needs to add nitrogen with a purity of ≥99.996% to make the oxygen content in the furnace ≤50PPM to prevent the regeneration of aluminum oxide. Therefore, the aluminum oxide film must be removed and its regeneration must be prevented during the brazing process.

[0085] Table 3 shows the state changes of the flux and the composite layer (i.e. solder) during the brazing process. Referring to Table 1, when the core of the microchannel heat exchanger 3 is located in the brazing zone 3, the flux begins to melt, and the chemical reaction equation when melting is: KAlF4-K3AlF6nH2O→KF+AI2O3+HF↑+H2O↑.

[0086] Table 3

[0087]

[0088]

[0089] It can be seen that the potassium fluoride KF generated after the reaction flows along with the solder on the solder surface and gathers to the lower surface of the manifold 33, the connection between the manifold 33 and the connecting tube 31, and the connection between the fin 32 and the connecting tube 31. When the core of the microchannel heat exchanger 3 is located in the cooling zone, the potassium fluoride KF is recrystallized at the lower surface of the manifold 33, the connection between the manifold 33 and the flat tube 31, and the connection between the fin 32 and the connecting tube 31.

[0090] The generated aluminum oxide AI2O3 and the broken aluminum oxide film on the surface of the part flow with the solder on the surface of the solder, and form an aluminum oxide film on the surface of the part when entering the cooling zone of the brazing furnace. The broken aluminum oxide film on the surface of the part and KF generate white crystals, i.e., brazing agent reactants, which drip along the outer surface of the manifold 33 to separate from the manifold 33, and the generated hydrogen fluoride HF and water vapor volatilize. In this way, the brazing agent residue on the microchannel heat exchanger 3 after brazing is effectively reduced. Although there is a small amount of brazing agent residue on the fin 32, it does not affect the corrosion resistance of the product.

[0091] Figure 8 FIG. 3 shows a schematic structural diagram of a first manifold 331 provided in an embodiment of the present application. Fig. 9 The schematic diagram of the structure of the second manifold 332 provided in the embodiment of the present application is shown. Figure 8 and Fig. 9 In some embodiments of the present application, the first manifold 331 includes a first manifold wall 3311, a first manifold cavity 3312 is formed on the inner side of the first manifold wall 3311, and a first port 3313 and a second port 3314 communicating with the first manifold cavity 3312 are provided on the outer side of the first manifold wall 3311. The second manifold 332 includes a second manifold wall 3321, a second manifold cavity 3322 is formed on the inner side of the second manifold wall 3321, and a third port 3323 and a fourth port 3324 communicating with the second manifold cavity 3322 are provided on the outer side of the second manifold wall 3321.

[0092] In this way, the first collecting chamber 3312 and the second collecting chamber 3322 can be used to collect refrigerant (i.e., heat exchange medium), the first port 3313 and the second port 3314 are used to control the inflow and outflow of refrigerant in the first collecting chamber 3312, and the third port 3323 and the fourth port 3324 are used to control the inflow and outflow of refrigerant in the second collecting chamber 3322.

[0093] It should be noted that the number of the collecting pipes 33 can be specifically set according to actual conditions.

[0094] Fig.10 FIG. 1 shows one of the structural diagrams of the connecting pipe 31 provided in the embodiment of the present application, see FIG. Fig.10The connecting tube 31 may be a plate-shaped flat tube, and a channel 311 is formed inside the connecting tube 31. The two ends of the connecting tube 31 are provided with a first opening 312 and a second opening 313 connected to the channel 311. The first opening 312 is connected to the second port 3314, and the second opening 313 is connected to the third port 3323. Figure 6 It can be seen that the refrigerant entering the first collecting chamber 3312 can enter the channel 311 of the connecting tube 31 through the second port 3314 and the first opening 312 in sequence, and then enter the multiple fins 32 connected to the connecting tube 31 through the channel 311. Through the contact between the fins 32 and the outside air, heat exchange is carried out through heat conduction and thermal radiation effects. Finally, the refrigerant after heat exchange enters the second collecting chamber 3322 through the second opening 313 and the third port 3323 in sequence.

[0095] In some embodiments of the present application, there are multiple connecting tubes 31, and the multiple connecting tubes 31 are arranged at intervals along the extension direction of the header 33. There are multiple second ports 3314 and multiple third ports 3323, and the multiple second ports 3314 are arranged at intervals along the extension direction of the first header 331, and the multiple third ports 3323 are arranged at intervals along the extension direction of the first header 332. The first openings 312 of the multiple connecting tubes 31 are connected one by one with the multiple second ports 3314 on the first header 331, and the second openings 313 of the multiple connecting tubes 31 are connected one by one with the multiple third ports 3323 on the first header 332.

[0096] It can be understood that the refrigerant in the microchannel heat exchanger 3 can flow into the multiple connecting tubes 31 through the multiple second ports 3314, and then exchange heat with the outside air through the fins 32. Since there are more connecting positions between the multiple connecting tubes 31 and the fins 32, the heat transfer efficiency of the multiple connecting tubes 31 to the fins 32 is faster. In other words, by providing multiple connecting tubes 31, the total flow rate of the refrigerant per unit time can be effectively increased, and the flow of the refrigerant in the fins 32 can be accelerated, thereby improving the heat exchange efficiency of the microchannel heat exchanger 3.

[0097] Fig.11 The second structural schematic diagram of the connecting pipe 31 provided in the embodiment of the present application is shown. Fig.12 The third structural diagram of the connecting pipe 31 provided in the embodiment of the present application is shown. Fig.11 and Fig.12 The connecting pipe 31 may also be a U-shaped flat tube, which can also play the role of transferring refrigerant.

[0098] In order to further improve the heat transfer efficiency of the microchannel heat exchanger 3, continue to refer to Figure 6In some embodiments, the number of fins 32 is multiple, and the multiple fins 32 are arranged at intervals along the extension direction of the connecting tube 31. In this way, since the refrigerant in the connecting tube 31 can exchange heat with the external air through the multiple fins 32, the heat exchange efficiency of the microchannel heat exchanger 3 is further improved.

[0099] In order to facilitate maintenance personnel to clean and maintain the manifold cavity inside the manifold 33, in some embodiments, Figure 8 In some embodiments of the present application, the first collecting pipe 331 is provided with an assembly port 3315 connected to the first collecting cavity 3312. The first collecting pipe 331 also includes an end cover 3316, which is arranged at the assembly port 3315 and is detachably connected to the first collecting pipe wall 3311. The end cover 3316 is used to open or close the assembly port 3315.

[0100] In this way, the user can open the assembly opening 3315 through the end cover 3316 , and use the assembly opening 3315 to perform related assembly work.

[0101] See also Fig.13 In some embodiments of the present application, the microchannel heat exchanger 3 further includes an inlet pipe 35 and an outlet pipe 36, one end of the inlet pipe 35 is used to communicate with one side of the refrigerant circulation component, and the other end of the inlet pipe 35 is connected to the first port 3313, one end of the outlet pipe 36 is connected to the other side of the refrigerant circulation component, and the other end of the outlet pipe 36 is connected to the fourth port 3324. In this way, the microchannel heat exchanger 3 is connected to the refrigerant circulation component through the inlet pipe 35 and the outlet pipe 36, and the refrigerant enters the microchannel heat exchanger 3 through the inlet pipe 35 to exchange heat with the outside air, and the refrigerant with a higher or lower temperature after heat exchange is returned to the refrigerant circulation component through the outlet pipe 36, forming a complete cooling / heating workflow.

[0102] In some embodiments, continue to refer to Fig.13 The microchannel heat exchanger 3 includes a first adapter seat 37 disposed between the inlet pipe 35 and the first header 331, and a second adapter seat 38 disposed between the outlet pipe 36 and the second header 332. The first adapter seat 37 is in communication with the first port 3313 of the first header 331, the second adapter seat 38 is in communication with the fourth port 3324 of the second header 332, the inlet pipe 35 is in communication with the first adapter seat 37, and the outlet pipe 36 is in communication with the second adapter seat 38. That is, the inlet pipe 35 is in communication with the first port 3313 of the first header 331 through the first adapter seat 37, and the outlet pipe 36 is in communication with the second port 3314 of the second header 332 through the second adapter seat 38.

[0103] In this way, the microchannel heat exchanger 3 can be connected to the refrigerant circulation component of the air-conditioning system through the inlet pipe 35, the outlet pipe 36, the first adapter seat 37 and the second adapter seat 38, and the connection is stable and convenient.

[0104] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. An air conditioner, characterized in that: include: A housing having a mounting cavity; A heat exchanger is located in the installation cavity; A refrigerant circulation component, connected to the heat exchanger to form a refrigerant circulation loop; A fan, used to drive air to flow through the heat exchanger; The heat exchanger comprises: The current collecting pipe comprises: a first current collecting pipe and a second current collecting pipe arranged at intervals; A connecting pipe is provided between the first current collecting pipe and the second current collecting pipe, and both ends of the connecting pipe are respectively welded to the first current collecting pipe and the second current collecting pipe, so that the first current collecting pipe and the second current collecting pipe are both connected to the connecting pipe; A plurality of fins are arranged at intervals along the extending direction of the connecting pipe and are all connected to the connecting pipe; Wherein, the material of the collecting tube is an aluminum alloy composite plate, and the aluminum alloy composite plate includes a base material layer and a composite layer arranged outside the base material layer, and the composite layer is the solder of the base material layer.

2. The air conditioner according to claim 1, characterized in that: The thickness of the substrate layer accounts for 85-95% of the total thickness of the aluminum alloy composite plate, and the composite layer accounts for 5-15% of the total thickness of the aluminum alloy composite plate.

3. The air conditioner according to claim 1, characterized in that: The composite layer is a four-series aluminum alloy.

4. The air conditioner according to claim 1, characterized in that: The connecting pipe is welded to the plurality of fins, and the connecting pipe is also made of the aluminum alloy composite plate.

5. The air conditioner according to claim 1, characterized in that: The first manifold comprises a first manifold wall, a first manifold cavity is formed on the inner side of the first manifold wall, and a first port and a second port communicating with the first manifold cavity are provided on the outer side of the first manifold wall. The second manifold comprises a second manifold wall, a second manifold cavity is formed on the inner side of the second manifold wall, and a third port and a fourth port communicating with the second manifold cavity are provided on the outer side of the second manifold wall; A channel is formed inside the communicating tube, and a first opening and a second opening communicating with the channel are formed at both ends of the communicating tube, the first opening communicates with the second port, and the second opening communicates with the third port.

6. The air conditioner according to claim 5, characterized in that: There are multiple communicating tubes, and the multiple communicating tubes are arranged at intervals along the extending direction of the collecting tube; The number of the second ports and the number of the third ports are both multiple, the multiple second ports are arranged at intervals along the extension direction of the first header, and the multiple third ports are arranged at intervals along the extension direction of the second header; The first openings of the plurality of connecting tubes are connected one by one with the plurality of second ports on the first header, and the second openings of the plurality of connecting tubes are connected one by one with the plurality of third ports on the second header.

7. The air conditioner according to claim 5, characterized in that: The first manifold is provided with an assembly port communicating with the first manifold cavity; The first header also includes: An end cover is arranged at the assembly port and is detachably connected to the first collecting pipe wall. The end cover is used to open or close the assembly port.

8. The air conditioner according to claim 5, characterized in that: The heat exchanger also includes: an inlet pipe, one end of which is used to communicate with one side of the refrigerant circulation component, and the other end of which is connected to the first port; and an outlet pipe, one end of which is connected to the other side of the refrigerant circulation component, and the other end of which is connected to the fourth port.

9. The air conditioner according to claim 5, characterized in that: The heat exchanger includes a first adapter seat arranged between an inlet pipe and the first header, and a second adapter seat arranged between an outlet pipe and the second header.

10. An air conditioner, characterized in that: include: A housing having a mounting cavity; A heat exchanger, wherein the heat exchanger is located inside the installation cavity; A refrigerant circulation component, the refrigerant circulation component is connected to the heat exchanger through a refrigerant pipeline; and a fan, for driving air to flow through the heat exchanger; The heat exchanger comprises: A current collecting pipe, the current collecting pipe comprising: a first current collecting pipe and a second current collecting pipe arranged at intervals; A connecting pipe, both ends of which are respectively welded to the first current collecting pipe and the second current collecting pipe, so that the first current collecting pipe and the second current collecting pipe are connected to the connecting pipe; A plurality of fins, wherein the plurality of fins are all arranged on the connecting pipe; Wherein, the material of the collecting tube is an aluminum alloy composite plate, and the aluminum alloy composite plate includes a base material layer and a composite layer arranged outside the base material layer, and the composite layer is the solder of the base material layer.

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