Microchannel heat exchanger and air conditioner

Abstract

This application relates to the field of air conditioner technology and discloses a microchannel heat exchanger and an air conditioner. The microchannel heat exchanger includes: multiple flat tubes, two manifolds, and at least one reversing valve. The reversing valve includes a valve body and a valve core. The valve core is configured to slide between a first position and a second position under the pressure of a fluid. When the valve core is in the first position, it blocks the first fluid inlet, and the second fluid inlet is connected to the fluid outlet. When the valve core is in the second position, it blocks the second fluid inlet, and the first fluid inlet is connected to the fluid outlet. In this application, the reversing valve changes the number of parallel flow paths of the flat tubes by allowing the refrigerant to flow in different directions in the flat tubes and manifolds. When the microchannel heat exchanger is used as an evaporator, the number of parallel flow paths of the flat tubes can be increased step by step, reducing pressure drop and improving heat absorption. When used as a condenser, the number of parallel flow paths of the flat tubes can be decreased step by step, increasing the refrigerant flow rate and improving heat release.

Description

Technical Field

[0001] This application relates to the field of air conditioner technology, and more particularly to a microchannel heat exchanger and an air conditioner. Background Technology

[0002] Microchannel heat exchangers are heat exchangers with channel hydraulic diameters of 100-1000 μm, including components such as manifolds, flat tubes, and fins.

[0003] When the air conditioner is in heating mode, the microchannel heat exchanger of the outdoor unit acts as an evaporator, where the refrigerant comes into contact with the outside air and absorbs heat, thus achieving the heating effect. When the air conditioner is in cooling mode, the microchannel heat exchanger of the outdoor unit acts as a condenser, where the refrigerant comes into contact with the outside air and releases heat, thus achieving the cooling effect.

[0004] However, whether used as an evaporator or a condenser, the number of parallel processes and the length of the process in a microchannel heat exchanger are fixed. It is impossible to dynamically adjust the number of parallel processes for evaporation and condensation conditions. As a result, when the microchannel heat exchanger is used as an evaporator to absorb heat, the refrigerant pressure drop is fast and the pressure loss is large, which affects the heat absorption effect. When used as a condenser to release heat, the refrigerant flow rate is slow and the heat exchange efficiency is low, which affects the heat release efficiency and prevents the microchannel heat exchanger from fully realizing its optimal performance. Utility Model Content

[0005] This application discloses a microchannel heat exchanger that can change the number of parallel passes in the flat tubes when the refrigerant flows in different directions in the flat tubes and manifolds via a reversing valve. When the microchannel heat exchanger is used as an evaporator, the number of parallel passes in the flat tubes can be increased step by step, reducing pressure drop, lowering pressure loss, and improving heat absorption efficiency. When used as a condenser, the number of parallel passes in the flat tubes can be decreased step by step, increasing the refrigerant flow rate and improving heat release efficiency.

[0006] To achieve the above objectives, according to a first aspect of this application, a microchannel heat exchanger is provided, comprising: a plurality of flat tubes arranged along a first direction; two manifolds, both extending along the first direction and disposed opposite to each other along a second direction, the second direction being perpendicular to the first direction; the plurality of flat tubes being located between the two manifolds; each flat tube communicating with both ends of the two manifolds along the first direction; each manifold having a first opening and a second opening; the first opening being for connection to an air conditioner compressor; and the second opening being for connection to an air conditioner throttle valve; and at least one reversing valve disposed in the manifolds, the reversing valve comprising: a valve body having a valve cavity formed therein; a fluid outlet facing the second direction; and a first fluid inlet and a second fluid inlet opposite to each other along the first direction; the fluid outlet and the first fluid inlet... Both the first fluid inlet and the second fluid inlet are connected to the valve cavity, and the fluid outlet is connected to a plurality of the flat tubes; the valve core is slidably disposed in the valve cavity along the first direction, and the valve core is configured to slide between a first position and a second position under the pressure of the fluid; when the valve core is in the first position, the valve core blocks the first fluid inlet so that the second fluid inlet is connected to the fluid outlet; when the valve core is in the second position, the valve core blocks the second fluid inlet so that the first fluid inlet is connected to the fluid outlet; the installation position of the reversing valve in the manifold is configured such that when the fluid enters the manifold through the first opening, the number of the parallel flat tubes decreases stepwise along the direction from the first opening to the second opening; when the fluid enters the manifold through the second opening, the number of the parallel flat tubes increases stepwise along the direction from the second opening to the first opening.

[0007] Thus, by using a reversing valve to change the refrigerant flow direction in the flat tube and the manifold, the number of parallel flow paths in the flat tube is altered, improving the heat exchange efficiency of the microchannel heat exchanger when it functions as an evaporator or a condenser. Compared to using multiple pairs of one-way valves in the manifold to switch between forward and reverse flow paths, which requires changing the number of parallel flat tubes, the reversing valve proposed in this embodiment requires fewer valve bodies. Each reversing valve can replace a pair of one-way valves. While meeting the requirement of automatic switching between forward and reverse flow paths, it also makes the overall structure of the microchannel heat exchanger more stable, reducing the probability of microchannel heat exchanger failure due to valve malfunction. Furthermore, the fewer valve bodies required, the lower the manufacturing cost.

[0008] As an optional implementation, there are multiple reversing valves, which are alternately arranged on two manifolds, and the reversing valves on the two manifolds are staggered in the second direction. The reversing valve adjacent to the first opening is arranged in the same manifold as the first opening, and the reversing valve adjacent to the second opening is arranged in the same manifold as the second opening.

[0009] In this way, by setting the position of each reversing valve, the refrigerant in the microchannel heat exchanger can flow in a roughly serpentine manner, thereby improving the heat exchange efficiency.

[0010] As an optional implementation, the plurality of directional valves include: a first directional valve, a second directional valve, and a third directional valve, wherein the number of flat tubes connected to the fluid outlet of the first directional valve is n1, the number of flat tubes connected to the fluid outlet of the second directional valve is n2, and the number of flat tubes connected to the fluid outlet of the third directional valve is n3; the number of flat tubes connected to the manifold between the first opening and the first directional valve is m1, the number of flat tubes connected to the manifold between the first directional valve and the second directional valve is m2, the number of flat tubes connected to the manifold between the manifold between the second directional valve and the third directional valve is m3, and the number of flat tubes connected to the manifold between the manifold between the third directional valve and the second opening is m4; when fluid enters from the first opening... When the fluid enters the manifold, the number of flat tubes connected in parallel along the direction from the first opening to the second opening are w1, w2, w3, and w4, respectively, where w1 = n1 + m1, w2 = n2 + m2, w3 = n3 + m3, w4 = 0 + m4, and the size relationship between w1, w2, w3, and w4 satisfies: w1 > w2 > w3 > w4; when the fluid enters the manifold through the second opening, the number of flat tubes connected in parallel along the direction from the second opening to the first opening are w1', w2', w3', and w4', respectively, where w1' = n1 + m4, w2' = n2 + m3, w3' = n3 + m2, w4' = 0 + m1, and the size relationship between w1', w2', w3', and w4' satisfies: w1' < w2' < w3' < w4'.

[0011] Thus, there can be three directional control valves: a first directional control valve, a second directional control valve, and a third directional control valve. The first directional control valve has seven flat tubes between its upper end and its first opening. Its fluid outlet can be connected to two flat tubes. The lower end of the first directional control valve and the upper end of the second directional control valve can have three flat tubes. The fluid outlet of the second directional control valve can be connected to two flat tubes. The lower end of the second directional control valve and the upper end of the third directional control valve can have one flat tube. The fluid outlet of the third directional valve can be connected to a flat pipe. There can also be a flat pipe between the lower end of the third valve and the second opening. Therefore, n1 = 2, n2 = 2, n3 = 1, m1 = 7, m2 = 3, m3 = 2, m4 = 1. When the fluid enters the manifold from the first opening, we can obtain w1 = n1 + m1 = 9, w2 = n2 + m2 = 5, w3 = n3 + m3 = 2, w4 = 0 + m4 = 1. Therefore, w... When the fluid enters the manifold through the second opening, w1' < w2' < w3' < w4'. When the fluid enters the manifold through the first opening, the relationship between w1, w2, w3, and w4 satisfies: w1 > w2 > w3 > w4. This ensures that the number of parallel flat tubes decreases progressively along the direction from the first opening to the second opening, reducing the pressure loss of the refrigerant during flow and improving the heat dissipation effect of the microchannel heat exchanger as an outdoor condenser. When the fluid enters the manifold through the second opening, the relationship between w1', w2', w3', and w4' satisfies: w1' < w2' < w3' < w4'. The number of parallel flat tubes increases progressively along the direction from the second opening to the first opening, increasing the velocity of the refrigerant during flow and improving the heat absorption effect of the microchannel heat exchanger as an outdoor evaporator.

[0012] As an optional implementation, the valve body includes: a first valve wall disposed within the manifold, and a first fluid inlet disposed on the first valve wall; a second valve wall disposed within the manifold, the second valve wall and the first valve wall being disposed opposite each other along the first direction, and a second fluid inlet disposed on the second valve wall; wherein, the fluid outlet is disposed between the first valve wall and the second valve wall, and along the second direction, each of the flat tubes corresponding to the region between the first valve wall and the second valve wall is connected to the fluid outlet.

[0013] In this way, the first valve wall can seal the upper and lower spaces at the corresponding position of the manifold, and the second valve wall can seal the upper and lower spaces at the corresponding position of the manifold, so that the reversing valve can divide the internal space of the manifold into multiple cavities. The length of the fluid outlet along the first direction can be the same as the distance between the first valve wall and the second valve wall, so that each of the flat tubes corresponding to the area between the first valve wall and the second valve wall is connected to the fluid outlet, maximizing the utilization of the internal space of the reversing valve.

[0014] As an optional implementation, along the second direction, both the first valve wall and the second valve wall are offset from each of the flat tubes.

[0015] In this way, the first valve wall and the second valve wall are installed in the manifold without overlapping with the flat tube, thus avoiding the first valve wall and / or the second valve wall from blocking the flat tube and affecting the normal function of the flat tube.

[0016] As an optional implementation, the reversing valve further includes: a third valve wall, the two ends of which are respectively connected to the first valve wall and the second valve wall along the first direction; a guide portion, which is disposed on the third valve wall and extends along the first direction, and the valve core is slidably disposed on the guide portion.

[0017] Thus, the valve core is slidably mounted on the guide section, and can slide stably along the first direction under the guidance of the guide section to stably reach the first position or the second position, ensuring the sealing effect on the first fluid inlet or the second fluid inlet.

[0018] As an optional implementation, the reversing valve further includes: a slider connected to the valve core; the guide portion is a guide groove disposed on the surface of the third valve wall facing the valve cavity, and the slider is slidably disposed in the guide groove.

[0019] In this way, the slider and the guide groove cooperate to slide, and the valve core is connected to the slider and slides with the slider. This can ensure that the valve core slides stably in the first direction and ensure that the valve core can effectively block the first fluid inlet or the second fluid inlet.

[0020] As an optional implementation, a baffle is provided in the fluid outlet, the baffle having a plurality of through holes extending through its body along the second direction.

[0021] In this way, the baffle can block part of the refrigerant flowing into the flat tube in the valve cavity, causing a portion of the refrigerant to flow back in the valve cavity. This allows the refrigerant in the valve cavity to mix more evenly and improves the heat exchange effect of the refrigerant.

[0022] As an optional implementation, each of the through holes is provided in a one-to-one correspondence with the flat tube along the second direction.

[0023] In this way, the through hole corresponds to the inlet of the flat tube, allowing the refrigerant in the valve cavity to smoothly enter the flat tube, which is more conducive to the flow of refrigerant and helps to improve the heat exchange effect of refrigerant.

[0024] According to an embodiment of the second aspect of this application, an air conditioner is provided, including the aforementioned microchannel heat exchanger.

[0025] Compared with the prior art, the beneficial effects of this application are:

[0026] The microchannel heat exchanger provided in this application embodiment can change the number of parallel passes in the flat tubes when the refrigerant flows in different directions in the flat tubes and manifolds via a reversing valve. This allows the number of parallel passes in the flat tubes to increase progressively when the microchannel heat exchanger is used as an evaporator, reducing pressure drop and pressure loss, and improving heat absorption efficiency. Conversely, when used as a condenser, the number of parallel passes in the flat tubes can decrease progressively, increasing the refrigerant flow velocity and improving heat release efficiency. Therefore, the microchannel heat exchanger can have excellent heat exchange performance whether used as an evaporator or a condenser, making air... The regulator can achieve better cooling performance in cooling mode and better heating performance in heating mode, thereby improving the user experience. Moreover, compared to setting multiple pairs of one-way valves to control the number of parallel processes, each reversing valve proposed in this application embodiment can replace a pair of one-way valves. This can significantly reduce the number of valves required in the microchannel heat exchanger while ensuring better heat exchange performance in both heating and cooling modes. As a result, the structure of the microchannel heat exchanger is simpler, more stable, more durable, and the cost is also reduced. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the microchannel heat exchanger disclosed in the embodiments of this application;

[0029] Figure 2 This is a schematic diagram of the structure of a microchannel heat exchanger with three reversing valves disclosed in an embodiment of this application;

[0030] Figure 3 The embodiments disclosed in this application Figure 2A schematic diagram of the flow path of a microchannel heat exchanger in which the fluid enters through the second opening;

[0031] Figure 4 The embodiments disclosed in this application Figure 2 A schematic diagram of the flow path and structure of a microchannel heat exchanger in which the fluid enters through the first opening;

[0032] Figure 5 This is a schematic cross-sectional view of the directional valve disclosed in an embodiment of this application;

[0033] Figure 6 This is a schematic cross-sectional view of the directional valve in the first position as disclosed in the embodiments of this application;

[0034] Figure 7 This is a schematic cross-sectional view of the directional valve in the second position as disclosed in the embodiments of this application.

[0035] Figure 8 This is a schematic diagram of the heat exchange system of the air conditioner when the air conditioner is in heating mode, as disclosed in the embodiments of this application.

[0036] Figure 9 This is a schematic diagram of the flow path of the heat exchange system of the air conditioner when it is in cooling mode, as disclosed in the embodiments of this application.

[0037] Explanation of reference numerals in the attached figures:

[0038] 100-Microchannel heat exchanger; 10-Flat tube; 20-Manifold; 21-First opening; 22-Second opening; 30-Reversing valve; 301-First reversing valve; 302-Second reversing valve; 303-Third reversing valve; 31-Valve body; 311-Valve cavity; 312-First valve wall; 313-Second valve wall; 314-Third valve wall; 3141-Guide groove; 32-Valve core; 3201-Slider; 321-First surface; 322-Second surface; 33-Fluid outlet; 35-First fluid inlet; 36-Second fluid inlet; 37-First elastic element; 38-Second elastic element; 39-Baffle; 391-Through hole; 40-Fin; 200-Compressor; 300-Throttle valve; 400-Four-way valve; 500-Indoor heat exchanger. Detailed Implementation

[0039] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0040] In this application, the terms "upper," "lower," "top," "bottom," "inner," "vertical," and "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated device, element, or component to having a specific orientation, or to be constructed and operated in a specific orientation.

[0041] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0042] Furthermore, the terms "set up," "equipped with," and "connected" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0043] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, elements, or components (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise stated, "a plurality of" means two or more.

[0044] Microchannel heat exchangers are heat exchangers with channel hydraulic diameters of 100-1000 μm.

[0045] The working principle of a microchannel heat exchanger is to transfer heat through heat transfer between the fluid and the heat exchange medium within the microchannel. When the fluid flows within the microchannel, due to the extremely small size of the microchannel, the temperature difference between the fluid and the channel wall causes heat transfer, and the fluid can quickly reach thermal equilibrium, thus achieving efficient heat exchange.

[0046] Microchannel heat exchangers mainly consist of structures such as manifolds, flat tubes, and fins. The manifolds collect and distribute the fluid, while the fluid flows within the channels formed by the flat tubes and exchanges heat with the surrounding walls.

[0047] Microchannel heat exchangers are used in air conditioners, serving as either evaporators or condensers in the outdoor unit. When the air conditioner is in heating mode, the microchannel heat exchanger in the outdoor unit acts as an evaporator. The inlet of the heat exchanger contains liquid refrigerant, and the outlet contains gaseous refrigerant. As the refrigerant flows through the microchannel heat exchanger, it comes into contact with the outside air, changing from liquid to gaseous refrigerant and absorbing heat to achieve the heating effect. When the air conditioner is in cooling mode, the microchannel heat exchanger in the outdoor unit acts as a condenser. Again, the inlet of the microchannel heat exchanger contains gaseous refrigerant, and the outlet contains liquid refrigerant. As the refrigerant flows through the microchannel heat exchanger, it comes into contact with the outside air, changing from gaseous to liquid refrigerant and releasing heat to achieve the cooling effect.

[0048] However, whether used as an evaporator or a condenser, the number of parallel processes and the length of the process in a microchannel heat exchanger are fixed. It is impossible to dynamically adjust the number of parallel processes for evaporation and condensation conditions. As a result, when the microchannel heat exchanger is used as an evaporator to absorb heat, the refrigerant pressure drop is fast and the pressure loss is large, which affects the heat absorption effect. When used as a condenser to release heat, the refrigerant flow rate is slow and the heat exchange efficiency is low, which affects the heat release efficiency and prevents the microchannel heat exchanger from fully realizing its optimal performance.

[0049] Based on this, this application provides a microchannel heat exchanger that can change the number of parallel passes in the flat tubes when the refrigerant flows in different directions in the flat tubes and manifolds via a reversing valve. When the microchannel heat exchanger is used as an evaporator, the number of parallel passes in the flat tubes can be increased step by step, reducing pressure drop, lowering pressure loss, and improving heat absorption efficiency. When used as a condenser, the number of parallel passes in the flat tubes can be decreased step by step, increasing the refrigerant flow rate and improving heat release efficiency.

[0050] The technical solution of this application will be further described below with reference to the embodiments and accompanying drawings.

[0051] Please see Figure 1 , Figure 1This is a schematic diagram of the microchannel heat exchanger 100 disclosed in an embodiment of this application. The microchannel heat exchanger 100 disclosed in this application includes: multiple flat tubes 10, two manifolds 20, and at least one reversing valve 30. The multiple flat tubes 10 are arranged along a first direction; the two manifolds 20 extend along the first direction and are arranged opposite each other along a second direction, which is perpendicular to the first direction. The multiple flat tubes 10 are located between the two manifolds 20, and both ends of each flat tube 10 along the first direction are respectively connected to the two manifolds 20. The manifolds 20 have a first opening 21 and a second opening 22. The first opening 21 is used to connect to the compressor 200 of an air conditioner, and the second opening 22 is used to connect to the throttling valve 300 of the air conditioner. Connection; a reversing valve 30 is disposed in the manifold 20. The reversing valve 30 includes: a valve body 31 and a valve core 32. A valve cavity 311 is formed within the valve body 31. The valve body 31 is provided with a fluid outlet 33 facing a second direction, and a first fluid inlet 35 and a second fluid inlet 36 opposite to each other along a first direction. The fluid outlet 33, the first fluid inlet 35, and the second fluid inlet 36 are all connected to the valve cavity 311. The fluid outlet 33 is connected to several flat tubes 10. The valve core 32 is slidably disposed within the valve cavity 311 along the first direction. The valve core 32 is configured to slide between a first position and a second position under the pressure of the fluid. Figure 6 As shown, Figure 6 This is a cross-sectional structural diagram of the reversing valve 30 in the first position as disclosed in the embodiments of this application. When the valve core 32 is in the first position, the valve core 32 blocks the first fluid inlet 35, so that the second fluid inlet 36 is connected to the fluid outlet 33, such as... Figure 7 As shown, Figure 7 This is a cross-sectional structural diagram of the reversing valve 30 in the first position as disclosed in the embodiment of this application. When the valve core 32 is in the second position, the valve core 32 blocks the second fluid inlet 36 so that the first fluid inlet 35 is connected to the fluid outlet 33. The installation position of the reversing valve 30 in the manifold 20 is configured such that when the fluid enters the manifold 20 through the first opening 21, the number of parallel flat tubes 10 decreases step by step along the direction from the first opening 21 to the second opening 22, and when the fluid enters the manifold 20 through the second opening 22, the number of parallel flat tubes 10 increases step by step along the direction from the second opening 22 to the first opening 21.

[0052] Specifically, the flat tube 10 can be a type of tubing with a flat cross-sectional shape. It has advantages such as light weight, high strength, and corrosion resistance. The interior of the flat tube 10 can consist of multiple microchannels with a width of less than 0.5 mm, and these channels can be rectangular, triangular, circular, or other shapes. The wall thickness can be set below 0.2 mm, resulting in high thermal conductivity. Furthermore, the interior can be specially treated to form a uniform alumina protective layer, providing strong corrosion resistance.

[0053] Fins 40 can be provided between each microchannel heat exchanger 100. The fins 40 can be made of metal materials, such as aluminum or copper, and are fixed between the flat tubes 10 by mechanical connection or welding. The fins 40 can increase the heat exchange area of ​​the heat exchanger, improve the heat exchange efficiency, and at the same time enhance the air turbulence, promoting heat exchange between the air and the flat tubes 10.

[0054] The fluid can be a refrigerant, which can exchange heat with the external environment. When the refrigerant flows in the manifold 20 and the flat tube 10, it can be a gas, a liquid, or a gas-liquid mixture.

[0055] The manifold 20 collects and distributes the refrigerant, allowing it to flow within the flat tubes 10 of the microchannel heat exchanger 100. The manifold 20 can be made of aluminum alloy, giving it good thermal conductivity, corrosion resistance, and machinability. Its low density helps reduce the weight of the heat exchanger, while its high strength allows it to withstand certain pressures. The manifold 20 has a first opening 21 and a second opening 22, which can be located on two separate manifolds 20 or both on a single manifold 20.

[0056] The reversing valve 30 is installed in the manifold 20. The reversing valve 30 can divide the internal space of the manifold 20 into multiple chambers. There can be one reversing valve 30. When there is one reversing valve 30, the first opening 21 and the second opening 22 are installed on one manifold 20. The reversing valve 30 is also installed in the manifold 20. The reversing valve 30 is not located in the middle of the manifold 20. That is, along the first direction, the number of flat tubes 10 on both sides of the reversing valve 30 is different.

[0057] The microchannel heat exchanger 100 proposed in this application embodiment can be used as an outdoor heat exchanger. When the microchannel heat exchanger 100 proposed in this application is used as an outdoor heat exchanger, the flow path of the heat exchange system of the air conditioner is as follows: Figure 8 and Figure 9 As shown, Figure 8 This is a schematic diagram of the heat exchange system of the air conditioner when it is in heating mode, as disclosed in the embodiments of this application. Figure 9 This is a schematic diagram of the flow path of the heat exchange system of the air conditioner when it is in cooling mode, as disclosed in the embodiments of this application. The heat exchange system may include a microchannel heat exchanger 100, an indoor heat exchanger 500, a compressor 200, a four-way valve 400, and a throttling valve 300. The indoor heat exchanger 500 has a third opening communicating with the compressor 200 and a fourth opening communicating with the throttling valve 300. The compressor 200 has an inlet and an outlet. The first opening 21 of the microchannel heat exchanger 100 is connected to the four-way valve 400, and then connected to the compressor 200 through the four-way valve 400. The second opening 22 is connected to the throttling valve 300. Figure 8 When the air conditioner is in heating mode, the microchannel heat exchanger 100, which serves as the outdoor heat exchanger, functions as an evaporator. The discharge port of the compressor 200 is connected to a four-way valve 400, which in turn connects to the third opening of the indoor heat exchanger 500. The fourth opening of the indoor heat exchanger 500 connects to a throttling valve 300, which in turn connects to the second opening 22 of the microchannel heat exchanger 100. The first opening 21 of the microchannel heat exchanger 100 connects to the four-way valve 400, which in turn connects to the air inlet of the compressor 200, forming a complete heat exchange loop that allows refrigerant to circulate within the loop. Figure 9 When the air conditioner is in cooling mode, the microchannel heat exchanger 100, which serves as the outdoor heat exchanger of the air conditioner, is used as a condenser. The discharge port of the compressor 200 is connected to the four-way valve 400, and then through the four-way valve 400, it is connected to the first opening 21 of the microchannel heat exchanger 100. The second opening 22 of the microchannel heat exchanger 100 is connected to the throttle valve 300, and the throttle valve 300 is connected to the fourth opening of the indoor heat exchanger 500. The third opening of the indoor heat exchanger 500 is connected to the four-way valve 400, and then through the four-way valve 400, it is connected to the air inlet of the compressor 200, forming a complete heat exchange circuit, allowing the refrigerant to circulate within the circuit.

[0058] Taking the microchannel heat exchanger 100 as an example of an outdoor unit of an air conditioner, when the microchannel heat exchanger 100 is used as an evaporator, the inlet of the heat exchanger is a liquid refrigerant. The liquid refrigerant can vaporize in the microchannel heat exchanger 100, absorbing heat during the vaporization process. During this process, the number of parallel flow paths of the flat tubes 10 inside the microchannel heat exchanger 100 is changed by the reversing valve 30 proposed in this embodiment, so that the number of parallel flow paths increases step by step, thereby reducing the pressure drop and slowing down the rate of pressure reduction, so that the liquid refrigerant can... The refrigerant can be converted into a gaseous refrigerant more efficiently, improving the heat absorption effect. When the air conditioner is in cooling mode, the microchannel heat exchanger 100 is used as a condenser. The inlet of the heat exchanger is a gaseous refrigerant, which releases heat and liquefies. Therefore, in this process, the number of parallel flow paths of the flat tubes 10 inside the microchannel heat exchanger 100 is changed by the reversing valve 30, so that the number of parallel flow paths is reduced step by step, thereby increasing the flow rate and thus increasing the refrigerant flow rate, making the heat exchange efficiency of the microchannel heat exchanger 100 higher and improving the heat release effect.

[0059] The number of parallel flow paths of the flat tube 10 refers to the number of adjacent flat tubes 10 with internal fluid flowing in the same direction among the multiple flat tubes 10 arranged along the first direction.

[0060] In this embodiment, the valve core 32 of the reversing valve 30 can slide under the pressure of the refrigerant. During the sliding process of the valve core 32, the flow path of the reversing valve 30 can be switched, so that the second fluid inlet 36 of the reversing valve 30 is connected to the fluid outlet 33, or the first fluid inlet 35 is connected to the fluid outlet 33. Thus, when the flow direction of the refrigerant is switched, the flow path of the refrigerant is automatically switched without the need for additional control structure.

[0061] In this embodiment of the application, the reversing valve 30 has a valve core 32 that can slide between a first position and a second position under the pressure of the fluid. When the valve core 32 is in the first position, it blocks the first fluid inlet 35 to allow the second fluid inlet 36 to communicate with the fluid outlet 33. When the valve core 32 is in the second position, it blocks the second fluid inlet 36 to allow the first fluid inlet 35 to communicate with the fluid outlet 33. Compared to setting multiple pairs of one-way valves in the manifold 20 to achieve forward and reverse flow path switching, which changes the number of parallel flat tubes 10, the reversing valve 30 proposed in this embodiment requires fewer valve bodies 31. Each reversing valve 30 can replace a pair of one-way valves. While meeting the requirement of automatic switching of forward and reverse flow paths, it can make the overall structure of the microchannel heat exchanger 100 more stable. The probability of the microchannel heat exchanger 100 failing due to valve body 31 malfunction is lower. Moreover, the number of valve bodies 31 is less, and the required manufacturing cost is also lower.

[0062] According to the embodiment of the present invention, the microchannel heat exchanger 100 can change the number of parallel passes of the flat tube 10 when the refrigerant flows in different directions in the flat tube 10 and the manifold 20 via the reversing valve 30. This allows the number of parallel passes of the flat tube 10 to increase progressively when the microchannel heat exchanger 100 is used as an evaporator, reducing pressure drop, lowering pressure loss, and improving heat absorption efficiency. Conversely, when used as a condenser, the number of parallel passes of the flat tube 10 can decrease progressively, increasing the refrigerant flow velocity and improving heat release efficiency. Therefore, the microchannel heat exchanger 100 can exhibit good heat exchange performance whether used as an evaporator or a condenser. The improved thermal performance allows the air conditioner to have better cooling performance in cooling mode and better heating performance in heating mode, thereby improving the user experience. Moreover, compared to setting multiple pairs of one-way valves to control the number of parallel processes, each reversing valve 30 proposed in this application embodiment can replace a pair of one-way valves. This can significantly reduce the number of valves required in the microchannel heat exchanger 100 while ensuring better heat exchange performance in both heating and cooling modes. As a result, the structure of the microchannel heat exchanger 100 is simpler, more stable, more durable, and the cost can also be reduced.

[0063] Combination Figure 2 , Figure 2This is a schematic diagram of the structure of a microchannel heat exchanger 100 with three reversing valves 30 disclosed in an embodiment of this application. In some embodiments, there are multiple reversing valves 30, which are alternately arranged on two manifolds 20, and the reversing valves 30 on the two manifolds 20 are staggered in a second direction. The reversing valve 30 adjacent to the first opening 21 and the first opening 21 are arranged in the same manifold 20, and the reversing valve 30 adjacent to the second opening 22 and the second opening 22 are arranged in the same manifold 20.

[0064] Specifically, when there are multiple reversing valves 30, they are alternately arranged on the two manifolds 20. That is, in the direction from the first opening 21 to the second opening 22, when the first reversing valve 30 is set on the first manifold 20, the second reversing valve 30 is set on the second manifold 20, and the third reversing valve 30 is set on the first manifold 20, and so on. If the number of reversing valves 30 is odd, the first opening 21 and the second opening 22 are both set in the same manifold 20. If the number of reversing valves 30 is even, the first opening 21 and the second opening 22 are set on two different manifolds 20, ensuring that the refrigerant in the microchannel heat exchanger 100 can flow in a roughly serpentine manner, thereby improving heat exchange efficiency.

[0065] Combination Figure 3 and Figure 4 , Figure 3 The embodiments disclosed in this application Figure 2 A schematic diagram of the flow path of the microchannel heat exchanger 100, in which the fluid enters through the second opening 22. Figure 4 The embodiments disclosed in this application Figure 2 A schematic diagram of the flow path structure of the microchannel heat exchanger 100 through which the fluid enters from the first opening 21. In some embodiments, the plurality of reversing valves 30 include: a first reversing valve 301, a second reversing valve 302, and a third reversing valve 303. The number of flat tubes 10 connected to the fluid outlet 33 of the first reversing valve 301 is n1, the number of flat tubes 10 connected to the fluid outlet 33 of the second reversing valve 302 is n2, and the number of flat tubes 10 connected to the fluid outlet 33 of the third reversing valve 303 is n3.

[0066] The number of flat tubes 10 connected between the first opening 21 and the first reversing valve 301 in the manifold 20 is m1; the number of flat tubes 10 connected between the first reversing valve 301 and the second reversing valve 302 in the manifold 20 is m2; the number of flat tubes 10 connected between the second reversing valve 302 and the third reversing valve 303 in the manifold 20 is m3; and the number of flat tubes 10 connected between the third reversing valve 303 and the second opening 22 in the manifold 20 is m4.

[0067] When the fluid enters the manifold 20 through the first opening 21, the number of flat tubes 10 connected in parallel along the direction from the first opening 21 to the second opening 22 are w1, w2, w3 and w4, respectively, where w1 = n1 + m1, w2 = n2 + m2, w3 = n3 + m3, w4 = 0 + m4, and the size relationship between w1, w2, w3 and w4 satisfies: w1 > w2 > w3 > w4;

[0068] When the fluid enters the manifold 20 through the second opening 22, the number of flat tubes 10 connected in parallel along the direction from the second opening 22 to the first opening 21 are w1', w2', w3' and w4', respectively, where w1' = n1 + m4, w2' = n2 + m3, w3' = n3 + m2, w4' = 0 + m1, and the size relationship between w1', w2', w3' and w4' satisfies: w1' < w2' < w3' < w4'.

[0069] Specifically, the number of flat tubes 10 connected in parallel along the direction from the first opening 21 to the second opening 22 is the number of parallel flow paths of the flat tubes 10, which is the number of adjacent flat tubes 10 with internal fluid flowing in the same direction among the multiple flat tubes 10 arranged along the first direction.

[0070] The number of reversing valves 30 can be three, namely the first reversing valve 301, the second reversing valve 302, and the third reversing valve 303. When fluid enters the manifold 20 through the first opening 21, such as Figure 2 As shown, it can be seen that there are 7 flat tubes 10 between the upper end of the first reversing valve 301 and the first opening 21; the fluid outlet 33 of the first reversing valve 301 is connected to 2 flat tubes 10; the lower end of the first reversing valve 301 and the upper end of the second reversing valve 302 have 3 flat tubes 10; the fluid outlet 33 of the second reversing valve 302 is connected to 2 flat tubes 10; the lower end of the second reversing valve 302 and the upper end of the third reversing valve 303 have 1 flat tube 10; the fluid outlet 33 of the third reversing valve 303 is connected to 1 flat tube 10; and the lower end of the third valve is connected to the second opening 22 with 1 flat tube 10. Therefore, it can be concluded that n1 = 2, n2 = 2, n3 = 1, m1 = 7, m2 = 3, m3 = 2, and m4 = 1. When the fluid enters the manifold 20 from the first opening 21, as... Figure 4 As shown, Figure 4 The direction of the middle arrow indicates the refrigerant flow direction. From this, we can deduce that w1 = n1 + m1 = 9, w2 = n2 + m2 = 5, w3 = n3 + m3 = 2, and w4 = 0 + m4 = 1. Therefore, w1 > w2 > w3 > w4. When the fluid enters the manifold 20 through the second opening 22, if... Figure 3 As shown, Figure 3The direction of the middle arrow indicates the direction of refrigerant flow. Its w1' = n1 + m4 = 2, w2' = n2 + m3 = 3, w3' = n3 + m2 = 5, w4' = 0 + m1 = 7, so we can conclude that w1' < w2' < w3' < w4'.

[0071] When the fluid enters the manifold 20 through the first opening 21, the magnitudes of w1, w2, w3, and w4 satisfy the following relationship: w1 > w2 > w3 > w4. This ensures that the number of parallel flat tubes 10 decreases progressively along the direction from the first opening 21 to the second opening 22, reducing the pressure loss of the refrigerant during flow and improving the heat dissipation effect of the microchannel heat exchanger 100 as an outdoor condenser. When the fluid enters the manifold 20 through the second opening 22, the magnitudes of w1', w2', w3', and w4' satisfy the following relationship: w1' < w2' < w3' < w4'. The number of parallel flat tubes 10 increases progressively along the direction from the second opening 22 to the first opening 21, increasing the velocity of the refrigerant during flow and improving the heat absorption effect of the microchannel heat exchanger 100 as an outdoor evaporator.

[0072] Combination Figure 5 , Figure 5 This is a schematic cross-sectional view of the reversing valve 30 disclosed in an embodiment of this application. In some embodiments, the valve body 31 includes: a first valve wall 312 and a second valve wall 313. The first valve wall 312 is disposed within the manifold 20, and a first fluid inlet 35 is disposed on the first valve wall 312. The second valve wall 313 is disposed within the manifold 20, and the second valve wall 313 and the first valve wall 312 are disposed opposite each other along a first direction. A second fluid inlet 36 is disposed on the second valve wall 313. The fluid outlet 33 is disposed between the first valve wall 312 and the second valve wall 313. Along a second direction, each flat tube 10 corresponding to the area between the first valve wall 312 and the second valve wall 313 is connected to the fluid outlet 33.

[0073] Specifically, the first valve wall 312 can seal the upper and lower spaces at the corresponding positions of the manifold 20, and the second valve wall 313 can seal the upper and lower spaces at the corresponding positions of the manifold 20, so that the reversing valve 30 can divide the internal space of the manifold 20 into multiple cavities. The length of the fluid outlet 33 along the first direction can be the same as the distance between the first valve wall 312 and the second valve wall 313, so that each flat tube 10 corresponding to the area between the first valve wall and the second valve wall 313 is connected to the fluid outlet 33, maximizing the utilization of the internal space of the reversing valve 30.

[0074] Furthermore, by adjusting the cavity length of the reversing valve 30, i.e. the distance between the first valve wall 312 and the second valve wall 313, the number of parallel processes and the process length under evaporation and condensation conditions can be adjusted, and reversing valves 30 of different lengths can be set to adapt to different needs.

[0075] Combination Figure 5 In some embodiments, along the second direction, the first valve wall 312 and the second valve wall 313 are both staggered from each of the flat tubes 10.

[0076] Specifically, the first valve wall 312 and the second valve wall 313 are installed in the manifold 20 without overlapping with the flat tube 10, so as to avoid the first valve wall 312 and / or the second valve wall 313 blocking the flat tube 10 and affecting the normal function of the flat tube 10.

[0077] In some embodiments, the reversing valve 30 further includes a third valve wall 314 and a guide portion, wherein the two ends of the third valve wall 314 along the first direction are respectively connected to the first valve wall 312 and the second valve wall 313; the guide portion is disposed on the third valve wall 314 and extends along the first direction, and the valve core 32 is slidably disposed on the guide portion.

[0078] Specifically, the valve core 32 is slidably mounted on the guide section, and can slide stably along the first direction under the guidance of the guide section to stably reach the first position or the second position, ensuring the sealing effect on the first fluid inlet 35 or the second fluid inlet 36.

[0079] In some embodiments, the reversing valve 30 further includes: a slider 3201 connected to the valve core 32; a guide portion is a guide groove 3141 disposed on the surface of the third valve wall 314 facing the valve cavity 311, and the slider 3201 is slidably disposed in the guide groove 3141.

[0080] Specifically, the slider 3201 slides in cooperation with the guide groove 3141, and the valve core 32 is connected to the slider 3201 and slides with the slider 3201. This ensures that the valve core 32 slides stably in the first direction, thus ensuring the sealing effect of the valve core 32 on the first fluid inlet 35 or the second fluid inlet 36.

[0081] In some embodiments, a baffle 39 is provided in the fluid outlet 33, the baffle 39 having a plurality of through holes 391 extending through its body in a second direction.

[0082] Specifically, the baffle 39 can block part of the refrigerant flowing into the flat tube 10 in the valve cavity 311, causing a portion of the refrigerant to flow back in the valve cavity 311, which can make the refrigerant in the valve cavity 311 mix more evenly and improve the heat exchange effect.

[0083] In some embodiments, along the second direction, each through hole 391 is provided in a one-to-one correspondence with the flat tube 10.

[0084] Specifically, the through hole 391 corresponds to the inlet of the flat tube 10, allowing the refrigerant in the valve chamber 311 to smoothly enter the flat tube 10, which is more conducive to the flow of refrigerant and helps to improve the heat exchange effect of refrigerant.

[0085] Please see Figures 1 to 9 This application discloses an air conditioner, including the aforementioned microchannel heat exchanger 100.

[0086] Specifically, the microchannel heat exchanger 100 in this embodiment can be used as an outdoor heat exchanger. The heat exchange system can also include an indoor heat exchanger 500, a compressor 200, a four-way valve 400, and a throttling valve 300, which can perform cooling or heating functions. Furthermore, the microchannel heat exchanger 100 proposed in this embodiment can enable the air conditioner to have good heat exchange effects when cooling and heating. Moreover, in the microchannel heat exchanger 100, the reversing valve 30 can replace the setting of multiple pairs of one-way valves, which can reduce the number of valves required, reduce costs, and make the structure of the microchannel heat exchanger 100 simpler, thereby improving the stability of the microchannel heat exchanger 100.

[0087] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A microchannel heat exchanger, used in an air conditioner, characterized in that, include: Multiple flat tubes (10) are arranged along a first direction; Two manifolds (20) are provided, both of which extend along a first direction and are arranged opposite each other along a second direction, the second direction being perpendicular to the first direction. A plurality of flat tubes (10) are located between the two manifolds (20). Each flat tube (10) is connected to both ends of the two manifolds (20) along the first direction. The manifolds (20) have a first opening (21) and a second opening (22). The first opening (21) is used to connect to the compressor (200) of the air conditioner, and the second opening (22) is used to connect to the throttle valve (300) of the air conditioner. At least one directional control valve (30) is disposed in the manifold (20), the directional control valve (30) comprising: A valve body (31) is provided, a valve cavity (311) is formed inside the valve body (31), a fluid outlet (33) is provided on the valve body (31), the fluid outlet (33) faces the second direction, and a first fluid inlet (35) and a second fluid inlet (36) are opposite to each other along the first direction. The fluid outlet (33), the first fluid inlet (35) and the second fluid inlet (36) are all connected to the valve cavity (311), and the fluid outlet (33) is connected to a plurality of the flat tubes (10). A valve core (32) is slidably disposed in the valve cavity (311) along the first direction. The valve core (32) is configured to slide between a first position and a second position under the pressure of the fluid. When the valve core (32) is in the first position, the valve core (32) blocks the first fluid inlet (35) so that the second fluid inlet (36) communicates with the fluid outlet (33). When the valve core (32) is in the second position, the valve core (32) blocks the second fluid inlet (36) so that the first fluid inlet (35) communicates with the fluid outlet (33). The reversing valve (30) is installed in the manifold (20) in such a way that when the fluid enters the manifold (20) through the first opening (21), the number of the parallel flat tubes (10) decreases step by step along the direction from the first opening (21) to the second opening (22), and when the fluid enters the manifold (20) through the second opening (22), the number of the parallel flat tubes (10) increases step by step along the direction from the second opening (22) to the first opening (21).

2. The microchannel heat exchanger according to claim 1, characterized in that, There are multiple reversing valves (30), which are alternately arranged on two manifolds (20), and the reversing valves (30) on the two manifolds (20) are staggered in the second direction. The reversing valve (30) adjacent to the first opening (21) and the first opening (21) are arranged in the same manifold (20), and the reversing valve (30) adjacent to the second opening (22) and the second opening (22) are arranged in the same manifold (20).

3. The microchannel heat exchanger according to claim 2, characterized in that, The plurality of the reversing valves (30) include: a first reversing valve (301), a second reversing valve (302) and a third reversing valve (303), wherein the number of flat tubes (10) connected to the fluid outlet (33) of the first reversing valve (301) is n1, the number of flat tubes (10) connected to the fluid outlet (33) of the second reversing valve (302) is n2, and the number of flat tubes (10) connected to the fluid outlet (33) of the third reversing valve (303) is n3. The number of flat tubes (10) connecting the manifold (20) between the first opening (21) and the first reversing valve (301) is m1; the number of flat tubes (10) connecting the manifold (20) between the first reversing valve (301) and the second reversing valve (302) is m2; the number of flat tubes (10) connecting the manifold (20) between the second reversing valve (302) and the third reversing valve (303) is m3; and the number of flat tubes (10) connecting the manifold (20) between the third reversing valve (303) and the second opening (22) is m4. When the fluid enters the manifold (20) through the first opening (21), the number of the flat tubes (10) connected in parallel along the direction from the first opening (21) to the second opening (22) are w1, w2, w3 and w4, respectively, where w1 = n1 + m1, w2 = n2 + m2, w3 = n3 + m3, w4 = 0 + m4, and the size relationship between w1, w2, w3 and w4 satisfies: w1 > w2 > w3 > w4; When the fluid enters the manifold (20) through the second opening (22), the number of the flat tubes (10) connected in parallel along the direction from the second opening (22) to the first opening (21) are w1', w2', w3' and w4', respectively, where w1' = n1 + m4, w2' = n2 + m3, w3' = n3 + m2, w4' = 0 + m1, and the size relationship between w1', w2', w3' and w4' satisfies: w1' < w2' < w3' < w4'.

4. The microchannel heat exchanger according to claim 1, characterized in that, The valve body (31) includes: The first valve wall (312) is disposed inside the manifold (20), and the first fluid inlet (35) is disposed on the first valve wall (312); The second valve wall (313) is disposed inside the manifold (20). The second valve wall (313) and the first valve wall (312) are disposed opposite to each other along the first direction. The second fluid inlet (36) is disposed on the second valve wall (313). The fluid outlet (33) is located between the first valve wall (312) and the second valve wall (313). Along the second direction, each of the flat tubes (10) corresponding to the area between the first valve wall (312) and the second valve wall (313) is connected to the fluid outlet (33).

5. The microchannel heat exchanger according to claim 4, characterized in that, Along the second direction, the first valve wall (312) and the second valve wall (313) are both offset from each of the flat tubes (10).

6. The microchannel heat exchanger according to claim 4, characterized in that, The reversing valve (30) also includes: The third valve wall (314) is connected to the first valve wall (312) and the second valve wall (313) at both ends along the first direction, respectively. A guide portion is disposed on the third valve wall (314) and extends along the first direction. The valve core (32) is slidably disposed on the guide portion.

7. The microchannel heat exchanger according to claim 6, characterized in that, The reversing valve (30) also includes: A slider (3201) is connected to the valve core (32); The guide part is a guide groove (3141), which is disposed on the surface of the third valve wall (314) facing the valve cavity (311), and the slider (3201) is slidably disposed in the guide groove (3141).

8. The microchannel heat exchanger according to claim 1, characterized in that, A baffle (39) is provided in the fluid outlet (33), the baffle (39) having a plurality of through holes (391) extending through its body along the second direction.

9. The microchannel heat exchanger according to claim 8, characterized in that, Along the second direction, each of the through holes (391) is provided in a one-to-one correspondence with the flat tube (10).

10. An air conditioner, characterized in that, The microchannel heat exchanger (100) as described in any one of claims 1-9.

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