Micro-channel heat exchanger and air conditioner with same

Abstract

The invention discloses a micro-channel heat exchanger and an air conditioner with the micro-channel heat exchanger. The micro-channel heat exchanger comprises a plurality of flat pipe sets and a collecting pipe, the collecting pipe is provided with a first refrigerant opening and a second refrigerant opening, and the flat pipe sets communicate with the collecting pipe to form a heat exchange flow path; the collecting pipes comprise a first collecting pipe and a second collecting pipe, partition plates are arranged in the first collecting pipe and the second collecting pipe, the first collecting pipe is divided into a plurality of first collecting cavities by the internal partition plates, and the second collecting pipe is divided into a plurality of second collecting cavities by the internal partition plates; the variable flow pipes comprise a first variable flow pipe and a second variable flow pipe, the first variable flow pipe is at least connected with two adjacent first flow collecting cavities, and the second variable flow pipe is at least connected with two adjacent second flow collecting cavities; the one-way valves comprise the first one-way valve and the second one-way valve so that the second variable flow pipe can flow in a one-way mode. The micro-channel heat exchanger has the advantages of being high in heat exchange efficiency, small in occupied space and the like.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, and in particular to a microchannel heat exchanger and an air conditioner having the same. Background Technology

[0002] In related technologies, air conditioners use heat exchangers as evaporators and condensers in evaporation and condensation modes, respectively. While the flow path of the heat exchanger piping remains constant in evaporation and condensation modes, the required optimal flow path or the number of parallel pipes differs. For example, when the heat exchanger in the outdoor unit of an air conditioner is used as an evaporator, the number of refrigerant flow paths is fixed, but this flow path is not the optimal flow path for condensation mode. The microchannel heat exchanger in the outdoor unit of an air conditioner cannot dynamically adjust the flow path according to the heat transfer characteristics of evaporation and condensation modes, thus failing to fully utilize the optimal overall performance of the microchannel heat exchanger.

[0003] Changing the flow path requires multiple distributors and on / off valves to achieve flow path switching. To achieve uniform flow distribution, adjustments to the distributor outlet pipe size, inlet pipe bending angle, and tilt angle are necessary, increasing design and manufacturing complexity and cost. Secondly, the small flow cross-sectional area of ​​the distributor leads to increased flow resistance at high flow rates. Furthermore, placing multiple distributors outside the heat exchanger increases the overall size of the heat exchanger, hindering its miniaturization. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, one object of the present invention is to provide a microchannel heat exchanger that can adjust the number of flow paths to adapt to different operating conditions in order to achieve optimal heat exchange performance, and has the advantages of high heat exchange efficiency and small footprint.

[0005] The present invention also proposes an air conditioner having the aforementioned microchannel heat exchanger.

[0006] To achieve the above objectives, a microchannel heat exchanger according to a first aspect of the present invention includes: a plurality of flat tube groups, the plurality of flat tube groups being arranged at intervals along a vertical direction, each of the flat tube groups including a plurality of horizontally extending flat tubes; a manifold, the manifold being connected to both ends of the flat tubes, the manifold being provided with a first refrigerant port and a second refrigerant port, the flat tube groups being in communication with the manifold to form a heat exchange flow path between the first refrigerant port and the second refrigerant port; the manifold including a first manifold and a second manifold, both the first manifold and the second manifold being constructed with partition plates, the first manifold being divided by the internal partition plates. The microchannel heat exchanger further includes: a multi-stage first manifold, and a multi-stage second manifold separated by an internal partition plate; wherein the microchannel heat exchanger also includes: a flow converter, comprising a first flow converter and a second flow converter, wherein the first flow converter connects to at least two adjacent first manifolds and the second flow converter connects to at least two adjacent second manifolds; and a check valve, comprising a first check valve and a second check valve, wherein the first check valve is connected to the first flow converter to allow unidirectional flow in the first flow converter and the second check valve is connected to the second flow converter to allow unidirectional flow in the second flow converter.

[0007] Therefore, the microchannel heat exchanger according to the embodiments of the present invention can adjust the number of flow paths to adapt to different operating conditions in order to achieve the best heat exchange performance, and has the advantages of high heat exchange efficiency and small space occupation.

[0008] According to some specific embodiments of the present invention, the second manifold has a gas pipe extending radially outward in the second manifold cavity at the top, and the first refrigerant port is formed in the gas pipe; the second manifold has a liquid pipe extending radially outward in the second manifold cavity at the bottom, and the second refrigerant port is formed in the liquid pipe; wherein, the second converter pipe is connected to the gas pipe.

[0009] According to some specific embodiments of the present invention, the first current collector connected to the first converter tube is connected to a plurality of the flat tube groups on the other side, and the second current collector connected to the second converter tube is connected to a plurality of the flat tube groups on the other side.

[0010] According to some specific embodiments of the present invention, at least one first current collector cavity located at the bottom is not connected to the first converter tube, while the remaining first current collector cavities are connected to the first converter tube; and / or At least one of the second current collectors located at the bottom is not connected to the second converter tube, while the remaining second current collectors are connected to the second converter tube.

[0011] According to some specific embodiments of the present invention, the first manifold is constructed with a plurality of pressure regulating orifice plates, the pressure regulating orifice plates dividing the first manifold cavity into a plurality of first diversion cavities, each of the first diversion cavities corresponding to one of the flat tube groups; and / or the second manifold is constructed with a plurality of pressure regulating orifice plates, the pressure regulating orifice plates dividing the second manifold cavity into a plurality of second diversion cavities, each of the second diversion cavities corresponding to one of the flat tube groups.

[0012] According to some specific embodiments of the present invention, both the first converter tube and the second converter tube are single-channel pipelines, the first converter tube is connected to two adjacent first collector cavities, and the second converter tube is connected to two adjacent second collector cavities.

[0013] According to some specific embodiments of the present invention, both the first converter pipe and the second converter pipe are branch pipes and each includes: a main flow pipe, wherein the main flow pipe of the first converter pipe is connected to a first manifold adjacent to the second refrigerant port, and the main flow pipe of the second converter pipe is connected to a second manifold adjacent to the first refrigerant port; and a plurality of branch pipes, wherein the plurality of branch pipes of the first converter pipe are connected one-to-one to the upper first manifold, and the plurality of branch pipes of the second converter pipe are connected one-to-one to the lower second manifold; wherein, the first check valve is connected to the main flow pipe of the first converter pipe, and the second check valve is connected to at least one branch pipe of the second converter pipe.

[0014] Furthermore, a portion of the plurality of shunt pipes includes a plurality of sub-shunt pipes, and the one-way valve is connected to at least one of the sub-shunt pipes.

[0015] According to some specific embodiments of the present invention, in the plurality of flat tube groups, the number of flat tubes in the topmost flat tube group is not less than the number of flat tubes in the other flat tube groups, and the number of flat tubes in the other flat tube groups is equal.

[0016] An air conditioner is provided according to a second aspect of the present invention, comprising: a refrigerant circuit in which refrigerant is circulated sequentially via a compressor, an indoor heat exchanger, an expansion valve, and an outdoor heat exchanger, wherein one of the outdoor heat exchanger and the indoor heat exchanger serves as a condenser and the other as an evaporator; the indoor heat exchanger and / or the outdoor heat exchanger is a microchannel heat exchanger as described in the above embodiments of the present invention.

[0017] The air conditioner according to the embodiments of the present invention has the advantages of high heat exchange efficiency, simple structure, and miniaturization by using the microchannel heat exchanger of the above embodiments of the present invention.

[0018] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0019] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the structure of a microchannel heat exchanger according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the first converter tube of a microchannel heat exchanger according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the second converter tube of a microchannel heat exchanger according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the evaporation operation of a microchannel heat exchanger according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the condensation operation of a microchannel heat exchanger according to an embodiment of the present invention; Figure 6 This is a schematic diagram of an embodiment of the microchannel heat exchanger according to the present invention, in which the bottom first collector cavity is not connected to the first converter tube; Figure 7 This is a schematic diagram of an embodiment of a microchannel heat exchanger according to the present invention, having a main flow tube and a branch flow tube; Figure 8 This is a schematic diagram of an embodiment of the microchannel heat exchanger with shunt tubes according to the present invention; Figure 9 This is a schematic diagram of the pressure regulating orifice plate of a microchannel heat exchanger according to an embodiment of the present invention; Figure 10 This is a schematic diagram of the overall structure of a microchannel heat exchanger according to an embodiment of the present invention; Figure label: Microchannel heat exchanger 1, flat tube assembly 100, flat tube 110, manifold 200, First refrigerant inlet 10, second refrigerant inlet 20 First manifold 210, second manifold 220, partition plate 230, first manifold cavity 201, second manifold cavity 202 Converter tube 300, first converter tube 310, second converter tube 320, one-way valve 400 First check valve 410, second check valve 420, air pipe 240, liquid pipe 250 Pressure regulating orifice plate 260, first flow divider 203 Mainstream tube 311, shunt tube 312, shunt sub-tube 313. Detailed Implementation

[0020] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0021] In the description of this invention, "first feature" and "second feature" may include one or more of the features.

[0022] In the description of this invention, "a plurality of" means two or more.

[0023] In the description of this invention, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or it may include the first and second features not being in direct contact but being in contact through another feature between them.

[0024] In the description of this invention, the terms "above," "over," and "on top" for the first feature and the second feature include the first feature being directly above or diagonally above the second feature, or simply indicating that the first feature is at a higher horizontal level than the second feature.

[0025] The microchannel heat exchanger 1 according to an embodiment of the present invention is described below with reference to the accompanying drawings.

[0026] like Figures 1-10 As shown, according to an embodiment of the present invention, a microchannel heat exchanger 1 is provided, comprising: multiple flat tube groups 100, a manifold 200, a converter tube 300, and a one-way valve 400.

[0027] Multiple flat tube groups 100 are arranged at intervals along the vertical direction, and each flat tube group 100 includes multiple horizontally extending flat tubes 110. A manifold 200 is connected to both ends of the flat tubes 110. The manifold 200 is provided with a first refrigerant port 10 and a second refrigerant port 20. The flat tube groups 100 are connected to the manifold 200 to form a heat exchange flow path between the first refrigerant port 10 and the second refrigerant port 20. The manifold 200 includes a first manifold 210 and a second manifold 220. Both the first manifold 210 and the second manifold 220 are equipped with partition plates 230. The first manifold 210 is divided into multiple first manifold chambers 201 by the internal partition plates 230, and the second manifold 220 is divided into multiple second manifold chambers 202 by the internal partition plates 230.

[0028] The converter tube 300 includes a first converter tube 310 and a second converter tube 320. The first converter tube 310 is connected to at least two adjacent first collector cavities 201, and the second converter tube 320 is connected to at least two adjacent second collector cavities 202. The one-way valve 400 includes a first one-way valve 410 and a second one-way valve 420. The first one-way valve 410 is connected to the first converter pipe 310 to make the first converter pipe 310 flow in one direction, and the second one-way valve 420 is connected to the second converter pipe 320 to make the second converter pipe 320 flow in one direction.

[0029] For example, the microchannel heat exchanger 1 refers to a heat exchanger with a channel hydraulic diameter of 100-1000 μm, and the flat tube assembly 100 is composed of multiple flat tubes 110 and fins. The microchannel heat exchanger 1 can be applied to either the outdoor or indoor unit of an air conditioner. Taking the outdoor unit as an example, in cooling mode, the microchannel heat exchanger 1 of the outdoor unit functions as a condenser, while in heating mode, it functions as an evaporator. It should be noted that when the air conditioner switches between cooling and heating modes, it adjusts the refrigerant flow direction through a four-way valve. That is, when the microchannel heat exchanger 1 functions as an evaporator, the first refrigerant port 10 becomes the inlet and the second refrigerant port 20 becomes the outlet; while when it functions as a condenser, the first refrigerant port 10 becomes the outlet and the second refrigerant port 20 becomes the inlet.

[0030] According to an embodiment of the microchannel heat exchanger 1, when the microchannel heat exchanger 1 is used as a condenser, such as Figure 5 As shown, the first refrigerant port 10 serves as the inlet for the gaseous refrigerant to flow in. During the flow process, the gaseous refrigerant gradually condenses into a liquid refrigerant and flows out from the outlet (the refrigerant flows from top to bottom). Because the refrigerant density gradually increases during condensation (changing from gaseous to liquid), the volumetric flow rate and velocity of the refrigerant gradually decrease. At this point, the refrigerant velocity becomes the main factor limiting heat transfer. To maintain good heat exchange performance, it is necessary to reduce the number of microchannel parallel flat tube groups 100, i.e., reduce the cross-sectional area of ​​the microchannel flow, in order to maintain high-speed refrigerant flow.

[0031] When the microchannel heat exchanger 1 is used as an evaporator, such as Figure 4As shown, the second refrigerant port 20 serves as the inlet for liquid refrigerant to flow in. During the flow process, the liquid refrigerant gradually evaporates into gaseous refrigerant and flows out from the outlet (the refrigerant flows from bottom to top). Because the refrigerant density gradually decreases during evaporation (changing from liquid to gas), the volumetric flow rate and velocity of the refrigerant gradually increase. At this point, the flow resistance of the refrigerant becomes the main factor restricting heat transfer (compared to the condenser, the evaporator operates in a low-temperature, low-pressure region, and temperature is sensitive to pressure changes. Increased flow resistance leads to increased pressure inside the evaporator, and the evaporation temperature also rises accordingly. This reduces the heat transfer temperature difference between the evaporation temperature and the ambient temperature, which is detrimental to heat exchange). To maintain good heat exchange performance, it is necessary to gradually increase the number of microchannel parallel flat tube groups 100, that is, gradually increase the cross-sectional area of ​​the microchannel flow, and reduce the refrigerant velocity and flow resistance.

[0032] Specifically, in evaporation conditions, such as Figure 4 As shown, liquid refrigerant flows into the second manifold 220 from the second refrigerant port 20 and flows in the flat tube assembly 100 in the direction of the arrow. When the refrigerant flows into the first manifold 210, part of the refrigerant continues to flow along the flat tube assembly 100, while the other part is diverted to the first converter pipe 310. Since the one-way valve 400 is in the conducting state during evaporation, the other part of the refrigerant can flow from bottom to top through the first converter pipe 310 and the first one-way valve 410 into the upper first manifold 201, and then flow along the upper flat tube assembly 100 towards the first refrigerant port 10. The two parts of the refrigerant form the same flow path in the same direction and flow side by side, and after passing through the second converter pipe 320 and the second one-way valve 420, they converge at the first refrigerant port 10 and flow out of the microchannel heat exchanger 1.

[0033] In condensation conditions, such as Figure 5 As shown, the gaseous refrigerant flows into the second manifold 220 from the first refrigerant port 10 and flows in the flat tube group 100 in the direction of the arrow. When the refrigerant flows into the first manifold 210, it continues to flow along the flat tube group 100. Since the first one-way valve 410 and the second one-way valve 420 are closed in the condensing condition, the refrigerant will not be split at the first converter tube 310 and the second converter tube 320. Thus, it always flows back and forth in the first manifold 210, the flat tube group 100 and the second manifold 220. The refrigerant between adjacent flat tube groups 100 forms a flow path with different directions and flows out of the microchannel heat exchanger 1 from the first refrigerant port 10.

[0034] In the aforementioned evaporation and condensation conditions, the one-way valve 400 alters the refrigerant's flow path. During evaporation, a unidirectional flow path is formed in a portion of the flat tube assembly 100, resulting in a larger flow area and fewer flow paths. This reduces refrigerant flow resistance and improves heat transfer during evaporation. During condensation, the refrigerant continuously flows back and forth along the flat tube assembly 100, resulting in a smaller flow cross-sectional area and higher flow velocity, which is more conducive to heat exchange. The longer flow distance also helps maintain a certain degree of subcooling at the condenser outlet, improving overall energy efficiency. Therefore, the microchannel heat exchanger 1 can adapt to different operating conditions by adjusting the number of flow paths to achieve optimal heat exchange performance.

[0035] Furthermore, the connection between the converter tube 300 and the manifold 200 is more suitable for the type of microchannel heat exchanger 1. The converter tube 300 is connected to the first manifold 210 and the second manifold 220 of the microchannel heat exchanger 1 through suitable connection points. As a result, flow path switching can be achieved without the need for a flow divider and on / off valve, and it does not occupy a large space outside the manifold 200, which is beneficial to the miniaturization of the overall size of the microchannel heat exchanger 1.

[0036] Therefore, the microchannel heat exchanger 1 according to the embodiments of the present invention can adjust the number of flow paths to adapt to different operating conditions in order to achieve the best heat exchange performance, and has the advantages of high heat exchange efficiency and small space occupation.

[0037] In some embodiments, such as Figure 1 As shown, the number of second manifolds 202 is greater than the number of first manifolds 201. For example, the number m of second manifolds 202 and the number n of first manifolds 201 satisfy m = n + 1. Flat tube assemblies 100 are connected between the first manifolds 201 and the second manifolds 202 to form a channel for refrigerant flow. Multiple flat tube assemblies 100 connected to the same first manifold 201 are connected to different second manifolds 202 on the other side, and flat tube assemblies 100 connected to the same second manifold 202 are connected to different first manifolds 201 on the other side.

[0038] In some specific embodiments of the present invention, such as Figure 1 As shown, the second manifold 220 has a gas pipe 240 extending radially outward in the second manifold cavity 202 at the top, and the first refrigerant port 10 is formed in the gas pipe 240. The second manifold 220 has a liquid pipe 250 extending radially outward in the second manifold cavity 202 at the bottom, and the second refrigerant port 20 is formed in the liquid pipe 250. The second converter pipe 320 is connected to the gas pipe 240.

[0039] When the microchannel heat exchanger 1 is in evaporation mode, the refrigerant in the second refrigerant pipe 320 can flow directly to the gas pipe 240 and out of the microchannel heat exchanger 1 without entering the second manifold 202, allowing the refrigerant to flow quickly out of the first refrigerant port 10 and further reducing the resistance to refrigerant flow. When the microchannel heat exchanger 1 is in condensation mode, if the refrigerant flowing in from the first refrigerant port 10 needs to be diverted, part of it can flow into the second manifold 202, and the other part can flow into the second refrigerant pipe 320 (the flow path other than the second check valve 420), thereby achieving rapid diversion and reducing flow resistance. If the refrigerant flowing in from the first refrigerant port 10 does not need to be diverted, it only flows into the second manifold 202, where the flow is interrupted at the closed second check valve 420 of the second refrigerant pipe 320.

[0040] When the variable flow path microchannel heat exchanger 1 is used as an evaporator or condenser, there should be no short circuit (the refrigerant flows directly out of the heat exchanger without passing through the flat tubes). At the same time, when the variable flow path microchannel heat exchanger 1 is used as an evaporator, the number of flat tube groups 100 gradually increases as the process proceeds, and when the variable flow path microchannel heat exchanger 1 is used as a condenser, the number of flat tube groups 100 gradually decreases as the process proceeds or remains unchanged.

[0041] In some specific embodiments of the present invention, such as Figure 4 and Figure 5 As shown, the first collector cavity 201, which is connected to the first converter tube 310, is connected to multiple flat tube groups 100 on the other side, and the second collector cavity 202, which is connected to the second converter tube 320, is connected to multiple flat tube groups 100 on the other side.

[0042] For example, the connection between the first converter tube 310 and the first manifold 210 is located between two adjacent flat tube groups 100. The refrigerant is diverted along the flow path of the first manifold 210, with a portion flowing into the first converter tube 310 and the other portion continuing to flow along the first manifold 210. Similarly, the connection between the second converter tube 320 and the second manifold 220 is located between two adjacent flat tube groups 100. The refrigerant is diverted along the flow path of the second manifold 220, with a portion flowing into the second converter tube 320 and the other portion continuing to flow along the second manifold 220. Thus, the positions of the first converter tube 310 and the second converter tube 320 are adapted to the positions of the flat tube groups 100, reducing the resistance to refrigerant flow and ensuring a smoother refrigerant flow process, which is beneficial for diversion.

[0043] In some specific embodiments of the present invention, such as Figure 6As shown, at least one first current collector 201 located at the bottom is not connected to the first converter tube 310, while the remaining first current collectors 201 are connected to the first converter tube 310; and / or at least one second current collector 202 located at the bottom is not connected to the second converter tube 320, while the remaining second current collectors 202 are connected to the second converter tube 320.

[0044] That is, the first and second manifolds 201 and 202, located at the positions indicated by the arrows on both sides, are not connected to the distribution pipe 300 to form a subcooled section. The first manifold 201 at the bottom does not have its flow split by the first converter pipe 310, and the second manifold 202 at the bottom does not have its flow split by the second converter pipe 320. The bottommost manifold and the connected flat tube assembly 100 together form a U-shaped subcooled section, thereby accommodating more liquid refrigerant at the bottom of the microchannel heat exchanger 1. By utilizing the lower temperature area at the bottom of the heat exchanger, the liquid refrigerant continues to release heat in the U-shaped tube, increasing the subcooling and thus enhancing heat exchange. Connecting the first converter pipe 310 in areas other than the subcooled section allows the flow path of the refrigerant inside the microchannel heat exchanger 1 to be changed during evaporation and condensation operations. This fully utilizes the role of the manifold 200 in increasing the subcooling and adapts to different operating conditions by adjusting the number of flow paths to achieve optimal heat exchange performance.

[0045] In some specific embodiments of the present invention, such as Figure 4 and Figure 5 As shown, the first manifold 210 has multiple pressure regulating orifice plates 260, which divide the first manifold 201 into multiple first branch chambers 203, each of which is connected to a flat tube group 100; and / or the second manifold 220 has multiple pressure regulating orifice plates 260, which divide the second manifold 202 into multiple second branch chambers (not shown in the figure), each of which is connected to a flat tube group 100.

[0046] For example, the pressure regulating orifice plate 260 can be a centrally located orifice or multiple orifices arranged circumferentially. The equivalent diameter of the orifice plate 2601 should not exceed the inner diameter of the converter tube 300 and the equivalent diameter of the flat tube assembly 100. By having small holes in the pressure regulating orifice plate 260, the first manifold 210 can be divided into multiple first distribution chambers 203, which facilitates the even distribution of refrigerant in the first manifold 201 to different first distribution chambers 203 and controls the pressure in each first distribution chamber 203. Similarly, a pressure regulating plate in the second manifold 220 can divide the second manifold 202 into multiple second distribution chambers, which facilitates the even distribution of refrigerant in the second manifold 202 to different second distribution chambers and controls the pressure in each second distribution chamber. Especially in condensation conditions, the downward-flowing refrigerant pressure regulation and distribution achieves sufficient heat exchange. Furthermore, regardless of whether the refrigerant has a high or low dryness, it can achieve good flow distribution to avoid generating additional resistance.

[0047] In some specific embodiments of the present invention, such as Figure 4 and Figure 5 As shown, both the first converter tube 310 and the second converter tube 320 are single-channel pipes. The first converter tube 310 is connected to two adjacent first collector cavities 201, and the second converter tube 320 is connected to two adjacent second collector cavities 202.

[0048] The first converter tube 310 and the second converter tube 320 of the single-channel pipeline have relatively simple structures. The two ends of the first converter tube 310 are connected to the first collector tube 210, and the two ends of the second converter tube 320 are connected to the second collector tube 220.

[0049] In evaporation conditions, such as Figure 4 As shown, liquid refrigerant flows into the second manifold 220 from the second refrigerant port 20 and flows in the flat tube assembly 100 in the direction of the arrow. When the refrigerant flows into the first manifold 210, part of the refrigerant continues to flow along the flat tube assembly 100, while the other part is diverted to the first converter pipe 310. Since the first one-way valve 410 and the second one-way valve 420 are in the conducting state during evaporation, the first converter pipe 310 of the single-channel pipeline provides a diversion path for the refrigerant. The refrigerant can flow from bottom to top through the first converter pipe 310 and the first one-way valve 410 into the upper first manifold 201, and then flow along the upper flat tube assembly 100 to the first refrigerant port 10. The other part of the refrigerant is diverted to the first converter pipe 310. The two parts of the refrigerant form the same flow path in the same direction and flow side by side, and then flow through the second converter pipe 320 and the second one-way valve 420 of the single-channel pipeline to the first refrigerant port 10 and out of the microchannel heat exchanger 1.

[0050] In condensation conditions, such as Figure 5As shown, the gaseous refrigerant flows into the second manifold 220 from the first refrigerant port 10 and flows in the flat tube group 100 in the direction of the arrow. When the refrigerant flows into the first manifold 210, it continues to flow along the flat tube group 100. Since the first one-way valve 410 and the second one-way valve 420 are closed in the condensing condition, and the first converter pipe 310 and the second converter pipe 320 are both single-channel pipes, the refrigerant will not be split at the first converter pipe 310 and the second converter pipe 320. Thus, it always flows back and forth in the first manifold 210, the flat tube group 100 and the second manifold 220. The refrigerant between adjacent flat tube groups 100 forms a flow path with different directions and flows out of the microchannel heat exchanger 1 from the first refrigerant port 10.

[0051] In some specific embodiments of the present invention, such as Figure 7 As shown, both the first converter tube 310 and the second converter tube 320 are shunt pipes and each includes: a main flow tube 311 and multiple shunt pipes 312.

[0052] The main flow pipe 311 of the first converter pipe 310 is connected to the first manifold 201 adjacent to the second refrigerant port 20, and the main flow pipe 311 of the second converter pipe 320 is connected to the second manifold 202 adjacent to the first refrigerant port 10. Multiple branch pipes 312 of the first converter pipe 310 are connected one-to-one to the upper first manifold 201, and multiple branch pipes 312 of the second converter pipe 320 are connected one-to-one to the lower second manifold 202.

[0053] The first check valve 410 is connected to the main flow pipe 311 of the first converter pipe 310, and the second check valve 420 is connected to at least one branch pipe 312 of the second converter pipe 320.

[0054] For example, the main flow pipe 311 of the first converter pipe 310 is connected to the first collector chamber 201 at the bottom, and the branch pipes 312 of multiple first converter pipes 310 are respectively connected to the adjacent first collector chambers 201 at the top, so that the refrigerant at the main flow pipe 311 of the first converter pipe 310 is diverted to the multiple first collector chambers 201 at the top during evaporation. The main flow pipe 311 of the second converter pipe 320 is connected to the upper second collector chamber 202 or liquid pipe 250, and the branch pipes 312 of multiple second converter pipes 320 are respectively connected to the adjacent second collector chambers 202 at the bottom, so that the refrigerant in different second collector chambers 202 is collected into the main flow pipe 311 of the second converter pipe 320 during evaporation.

[0055] Therefore, in evaporation conditions, such as Figure 7As shown by the solid arrow, the branch pipe 312 of the first converter pipe 310 diverts the refrigerant to the first collector chamber 201 and then flows through the flat tube group to the second collector chamber 202 on the other side. The branch pipe 312 of the second flat tube group receives the refrigerant in the second collector chamber 202 and collects it in the main pipe 311. Since the first one-way valve 410 and the second one-way valve 420 are in the conducting state, the refrigerant is diverted again by the multiple branch pipes 312 of the first converter pipe 310, and collected by the multiple branch pipes 312 of the second converter pipe 320, so that the refrigerant flows in the same direction and in parallel in the flat tube group 100. Finally, it flows out of the microchannel heat exchanger 1 through the second converter pipe 320 and the second one-way valve 420 to the first refrigerant port 10. Therefore, by utilizing the guiding effect of the first flow converter 310 and the second flow converter 320 in the flow distribution pipeline, the refrigerant has a larger flow cross-sectional area in the flow path of the flat tube group 100, and the refrigerant flow velocity is reduced accordingly. The heat transfer effect is improved by reducing the refrigerant flow resistance.

[0056] Furthermore, the second one-way valve 420 is connected to at least one branch pipe 312 of the second converter pipe 320. In condensation mode, such as... Figure 7 As shown by the dashed arrow, the second one-way valve 420 blocks the second flow converter 320. At this time, the refrigerant flows from other branch pipes 312 without the second one-way valve 420 to the second manifold 202, thus serving as a flow divider. It can be understood that in the evaporation state, since both the first one-way valve 410 and the second one-way valve 420 are open, flow division can occur. However, in the condensation state, since both the first one-way valve 410 and the second one-way valve 420 are closed, flow division can only occur in the branch pipe 312 without the second one-way valve 420. Therefore, in the evaporation state, the flow division results in a larger number of flow stages, while in the condensation state, the number of flow stages results in a smaller number of flow stages. This leads to lower resistance in the evaporation state and a longer flow distance in the condensation state, ensuring smooth flow path switching under different operating conditions.

[0057] Furthermore, such as Figure 8 As shown, some of the multiple shunt pipes 312 include multiple shunt sub-pipes 313, and a one-way valve is connected to at least one shunt sub-pipe 313.

[0058] Taking evaporation as an example, the refrigerant flowing in from the second refrigerant inlet 20 flows through the flat tube group 100 to the first manifold 210. On one side of the first manifold 210, after being split by the branch pipe 312, a portion of the branch pipe 312 can further split into multiple branch sub-pipes 313. One branch pipe 312 is directly connected to the lower-positioned first branch cavity 203, while the branch sub-pipes 313 can be connected to adjacent first branch cavities 203. Thus, the refrigerant undergoes multiple stages of splitting in the flow converter. Furthermore, depending on the different microchannel heat exchangers 1, even more types of parallel flat tube groups 100 and branching stages can be formed, which will not be elaborated here. Since the more branching stages there are, the more difficult it is to achieve uniform flow distribution, it is recommended that the number of branching stages be less than or equal to three.

[0059] In some specific embodiments of the present invention, among the multiple flat tube groups 100, the number of flat tubes in the topmost flat tube group 100 is not less than the number of flat tubes 110 in the other flat tube groups 100, and the number of flat tubes 110 in the other flat tube groups 100 is equal.

[0060] In evaporation mode, the upper flat tube assembly 100 has a larger number of flat tubes 110, allowing the refrigerant to flow from bottom to top. This increases the flow area near the first refrigerant inlet 10, reducing flow resistance and improving thermal efficiency. In condensation mode, the number of flat tubes in the upper flat tube assembly 100 decreases from top to bottom, reducing the flow area near the second refrigerant inlet 20. This allows the refrigerant to flow at a higher speed, facilitating heat exchange, ensuring a certain degree of subcooling, and improving overall energy efficiency.

[0061] The air conditioner according to an embodiment of the present invention is described below.

[0062] An air conditioner according to an embodiment of the present invention includes: a refrigerant circuit in which refrigerant is circulated sequentially through a compressor, an indoor heat exchanger, an expansion valve and an outdoor heat exchanger, wherein one of the outdoor heat exchanger and the indoor heat exchanger serves as a condenser and the other serves as an evaporator; The indoor heat exchanger and / or outdoor heat exchanger is the microchannel heat exchanger 1 described in the above embodiments of the present invention.

[0063] The refrigerant flows inside the microchannel heat exchanger 1, and uses the heat absorption or release during the evaporation or condensation of the refrigerant to exchange heat with the air outside the microchannel heat exchanger 1, thereby achieving the cooling or heating effect of the air conditioner.

[0064] Taking the microchannel heat exchanger 1 of the outdoor unit of the air conditioner as an example, when the air conditioner is running in cooling and heating modes respectively, the microchannel heat exchanger 1 is used as a condenser and an evaporator. It should be noted that when the air conditioner switches between cooling and heating modes, it will adjust the flow direction of the refrigerant through a four-way valve. The first refrigerant port 10 is the outlet in the evaporation mode and the inlet in the condensation mode, and the second refrigerant port 20 is the inlet in the evaporation mode and the outlet in the condensation mode.

[0065] The air conditioner of this invention uses the microchannel heat exchanger 1 of the above embodiment, and connects the converter tube 300 and the one-way valve 400 through the manifold 200. By utilizing the flow splitting function of the manifold 200 itself, the flow path can be switched between evaporation and condensation conditions, giving full play to the heat exchange performance of the microchannel heat exchanger 1. At the same time, it replaces the flow splitter and other structures in related technologies. The pipe size does not need to be adjusted, and the material and manufacturing cost of the heat exchanger is also reduced.

[0066] Therefore, the air conditioner according to the embodiments of the present invention has advantages such as high heat exchange efficiency, simple structure, and advantages for miniaturization.

[0067] Other configurations and operations of the microchannel heat exchanger 1 and the air conditioner according to embodiments of the present invention are known to those skilled in the art and will not be described in detail here.

[0068] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0069] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A microchannel heat exchanger, comprising: Multiple flat tube groups are arranged at intervals along the vertical direction, and each flat tube group includes multiple horizontally extending flat tubes. The manifold is connected to both ends of the flat tube. The manifold is provided with a first refrigerant port and a second refrigerant port. The flat tube assembly is connected to the manifold to form a heat exchange flow path between the first refrigerant port and the second refrigerant port. The feature is that the manifold includes a first manifold and a second manifold, both of which are constructed with a partition plate. The first manifold is divided into multiple first manifold cavities by the internal partition plate, and the second manifold is divided into multiple second manifold cavities by the internal partition plate. The microchannel heat exchanger further includes: The converter tube includes a first converter tube and a second converter tube, wherein the first converter tube is connected to at least two adjacent first collector cavities, and the second converter tube is connected to at least two adjacent second collector cavities. A one-way valve, comprising a first one-way valve and a second one-way valve, wherein the first one-way valve is connected to the first converter pipe to allow unidirectional flow in the first converter pipe, and the second one-way valve is connected to the second converter pipe to allow unidirectional flow in the second converter pipe.

2. The microchannel heat exchanger according to claim 1, characterized in that, The second manifold has a gas pipe extending radially outward in the second manifold cavity at the top, and the first refrigerant port is formed in the gas pipe. The second manifold has a liquid pipe extending radially outward in the second manifold cavity at the bottom, and the second refrigerant port is formed in the liquid pipe. The second converter tube is connected to the gas tube.

3. The microchannel heat exchanger according to claim 1, characterized in that, The first collector cavity connected to the first converter tube is connected to a plurality of the flat tube groups on the other side, and the second collector cavity connected to the second converter tube is connected to a plurality of the flat tube groups on the other side.

4. The microchannel heat exchanger according to claim 1, characterized in that, At least one of the first current collectors located at the bottom is not connected to the first converter tube, while the remaining first current collectors are connected to the first converter tube; and / or At least one of the second current collectors located at the bottom is not connected to the second converter tube, while the remaining second current collectors are connected to the second converter tube.

5. The microchannel heat exchanger according to claim 1, characterized in that, The first manifold has multiple pressure regulating orifice plates that divide the first manifold into multiple first branch chambers, each of which is connected to one of the flat tube groups; and / or The second manifold has multiple pressure regulating orifice plates inside, which divide the second manifold into multiple second branch chambers. Each second branch chamber is connected to one of the flat tube groups.

6. The microchannel heat exchanger according to claim 1, characterized in that, Both the first converter tube and the second converter tube are single-channel pipes. The first converter tube is connected to two adjacent first collector cavities, and the second converter tube is connected to two adjacent second collector cavities.

7. The microchannel heat exchanger according to claim 1, characterized in that, Both the first converter tube and the second converter tube are shunt tubes and each includes: Main flow pipe, the main flow pipe of the first converter pipe is connected to the first manifold adjacent to the second refrigerant port, and the main flow pipe of the second converter pipe is connected to the second manifold adjacent to the first refrigerant port; Multiple shunt tubes, the multiple shunt tubes of the first converter tube are connected one-to-one to the first current collection cavity at the upper part, and the multiple shunt tubes of the second converter tube are connected one-to-one to the second current collection cavity at the lower part. The first check valve is connected to the main flow pipe of the first converter pipe, and the second check valve is connected to at least one branch pipe of the second converter pipe.

8. The microchannel heat exchanger according to claim 7, characterized in that, A portion of the plurality of shunt pipes includes a plurality of sub-shunt pipes, and the one-way valve is connected to at least one of the sub-shunt pipes.

9. The microchannel heat exchanger according to claim 1, characterized in that, In the plurality of flat tube groups, the number of flat tubes in the topmost flat tube group is not less than the number of flat tubes in the other flat tube groups, and the number of flat tubes in the other flat tube groups is equal.

10. An air conditioner, comprising: The refrigerant circuit circulates the refrigerant sequentially through the compressor, indoor heat exchanger, expansion valve, and outdoor heat exchanger. One of the outdoor heat exchanger and the indoor heat exchanger serves as a condenser, and the other serves as an evaporator. The feature is that the indoor heat exchanger and / or the outdoor heat exchanger is a microchannel heat exchanger as described in any one of claims 1-9.

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