Fluid distribution structure, heat exchanger, outdoor unit and air conditioner

Abstract

The application provides a fluid distribution structure, a heat exchanger, an outdoor unit and an air conditioner. The fluid distribution structure comprises a first collecting pipe and a first flow guide pipe. The first collecting pipe is annular, and a first annular flow channel is formed in the inner cavity of the first collecting pipe. A plurality of first connecting holes are arranged on the first end face of the first collecting pipe, and the first connecting holes are used for connecting with flat tubes. The first flow guide pipe comprises a flow guide pipe body and an elbow pipe which are connected with each other. The first end of the flow guide pipe body extends out of the first collecting pipe. The second end of the flow guide pipe body and the first end of the elbow pipe are communicated with each other. The inner cavities of the flow guide pipe body and the elbow pipe form a bent flow guide channel. The second end of the elbow pipe is connected with the first collecting pipe or arranged in the first collecting pipe. The bent flow guide channel is communicated with the first annular flow channel. The annular first collecting pipe can uniformly distribute refrigerant in the heat exchanger, improve the heat exchange efficiency, and the arrangement of the elbow pipe can reduce the resistance in the fluid flow process.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of air conditioners, and particularly relates to a fluid distribution structure, a heat exchanger, an outdoor unit and an air conditioner. BACKGROUND

[0002] An air conditioner can provide a strong guarantee for a comfortable living environment, and its heat exchanger mainly includes a finned tube heat exchanger and a micro-channel heat exchanger. Compared with the finned tube heat exchanger, the micro-channel heat exchanger can effectively reduce the refrigerant injection amount and improve the economy, and is widely concerned and researched and developed by enterprises. The micro-channel heat exchanger has many branches, and the manifold and the micro-channel flat tube have resistance. When the heat exchanger is used as an evaporator, there is a problem of uneven distribution of the refrigerant when the distribution pipe distributes the refrigerant to the micro-channel flat tube, which directly affects the heat exchange efficiency of the heat exchanger, causes the power consumption to increase, and reduces the economy and comfort. The refrigerant needs to be evenly distributed to the inlet flat tube. It is imperative to provide a new distribution structure for the micro-channel heat exchanger to improve the uniformity of distribution to reduce the flow resistance and improve the performance.

[0003] In the related art, an air conditioner heat exchanger is disclosed, wherein the first distribution structure has a ladder-shaped communication structure, and the refrigerant is in the communication cavity to form a circulating flow mixture, so that the gas-liquid two-phase refrigerant flowing in is fully mixed and evenly distributed, and the refrigerant can enter the heat exchange pipe in the form of uniform mist. However, the circulating flow needs to overcome the influence of gravity of the entire height of the heat exchanger, the influence of the right-angle turn, and the influence of the small-diameter connecting pipe, the structure is complex, the pressure loss is large, and the overall performance of the system is affected.

[0004] In the related art, a flow uniform distribution device is disclosed, which includes a distribution mechanism, the distribution mechanism, a buffer cavity and an inlet pipe are sequentially communicated, an ascending pipe and a descending branch pipe, a first distribution cavity and a second distribution cavity are sequentially arranged from inside to outside, and a plurality of descending branch pipes are distributed along the circumference of the ascending pipe, so that the distribution problem of the double-row micro-channel heat exchanger under the condition of many branches is solved. However, the distribution structure is complex, is not easy to mass-produce, the refrigerant repeatedly flows upward and downward, the energy loss is serious, the pressure loss is large, and the overall performance of the system is affected. SUMMARY

[0005] The present application provides a fluid distribution structure, a heat exchanger, an outdoor unit and an air conditioner, which can solve the technical problem that the refrigerant in the manifold is unevenly distributed to each micro-channel flat tube when the refrigerant is distributed due to the need to overcome gravity and flow resistance.

[0006] The present application provides a fluid distribution structure, which includes a first manifold and a first flow guide pipe;

[0007] The first manifold is annular, and a first annular flow channel is formed in the inner cavity of the first manifold along the circumference of the first manifold. A plurality of first connecting holes are arranged on the first end face of the first manifold, and the first connecting holes are used for connecting with flat tubes.

[0008] The first flow guide pipe comprises a flow guide pipe body and a bend pipe connected with each other, a first end of the flow guide pipe body extends out of the first collecting pipe, a second end of the flow guide pipe body and a first end of the bend pipe communicate with each other, an inner cavity of the flow guide pipe body and the bend pipe forms a bent flow guide channel, a second end of the bend pipe is connected with the first collecting pipe or is arranged in the first collecting pipe, and the bent flow guide channel communicates with the first annular flow channel.

[0009] In some embodiments, the bend pipe is in an L shape, and in the axial direction of the flow guide pipe body, the second end of the bend pipe is arranged in a bent manner in a first direction, and the second end of the bend pipe is connected with the first collecting pipe.

[0010] In some embodiments, the bend pipe comprises a first pipe segment and a second pipe segment connected with each other, one end of the first pipe segment away from the second pipe segment communicates with the flow guide pipe body, the second pipe segment is in a necked structure, and one end of the second pipe segment away from the first pipe segment extends into the first collecting pipe.

[0011] In some embodiments, the bend pipe is in a bifurcated structure, and the bend pipe is arranged in the first collecting pipe.

[0012] In some embodiments, the bend pipe comprises a first branch pipe segment and a second branch pipe segment, one end of the first branch pipe segment and one end of the second branch pipe segment both communicate with the flow guide pipe body, in the axial direction of the flow guide pipe body, the other end of the first branch pipe segment is arranged in a bent manner in a first direction, the other end of the second branch pipe segment is arranged in a bent manner in a second direction, a first branch flow channel is formed between the first branch pipe segment and the flow guide pipe body, and a second branch flow channel is formed between the second branch pipe segment and the flow guide pipe body.

[0013] In some embodiments, the first collecting pipe comprises a collecting pipe body and a connecting pipe body, the collecting pipe body has a first end head and a second end head away from each other, the first end head and the second end head are arranged in a closed manner, the first end head is provided with a first communication hole, the second end head is provided with a second communication hole, two ends of the connecting pipe body are connected with the first communication hole and the second communication hole respectively, an inner cavity of the connecting pipe body forms a connecting flow channel, the connecting flow channel communicates with the first annular flow channel, and the second end of the bend pipe is connected with the first end head.

[0014] In some embodiments, the second manifold is annular, and an inner cavity of the second manifold forms a second annular flow channel along a circumferential direction of the second manifold; a first end surface of the second manifold is provided with a plurality of second connecting holes for connecting with the flat tubes; the first manifold and the second manifold are respectively arranged at two ends of the flat tubes; and a first end of the second flow guide tube extends out of the second manifold, and a second end of the second flow guide tube is connected with the second manifold.

[0015] In some embodiments, the second end of the second flow guide tube is closed and extends into the second manifold; an inner cavity of the second flow guide tube has a straight-through flow guide channel; and an outer wall of the second end of the second flow guide tube is provided with a flow guide through hole, and the straight-through flow guide channel communicates with the second annular flow channel through the flow guide through hole.

[0016] In some embodiments, the outer wall of the second end of the second flow guide tube is provided with at least two flow guide through holes, and the first flow guide through hole and the second flow guide through hole are oppositely arranged to form a first shunt channel and a second shunt channel between the straight-through flow guide channel and the second annular flow channel.

[0017] In some embodiments, along the circumferential direction of the second manifold, the first end surface of the second manifold has a first region and a second region; the plurality of second connecting holes are arranged in the first region; the second region is a non-hole region; an outer peripheral wall of the second manifold is provided with a flow guide connecting hole, the second end of the second flow guide tube extends into the second manifold through the flow guide connecting hole, and the flow guide through hole is correspondingly arranged with the second region.

[0018] A heat exchanger includes a fluid distribution structure, a plurality of micro-channel flat tubes, and a plurality of fins, the fluid distribution structure is the fluid distribution structure described above, the plurality of micro-channel flat tubes are arranged at intervals along a circumferential direction of the first manifold, and the plurality of fins are arranged at intervals along an axial direction of the micro-channel flat tubes.

[0019] In some embodiments, the fin is annular, and an inner diameter and an outer diameter of the fin are smaller than an inner diameter and an outer diameter of the first manifold; a plurality of clamping grooves are arranged on the fin along a circumferential direction of the fin, and the clamping grooves are connected with the micro-channel heat exchange flat tubes.

[0020] An outdoor unit includes a heat exchanger, and the heat exchanger is the heat exchanger described above.

[0021] An air conditioner includes an outdoor unit, and the outdoor unit is the outdoor unit described above.

[0022] The fluid distribution structure, the heat exchanger, the outdoor unit, and the air conditioner provided by the application have the following beneficial effects:

[0023] The present application improves the vertical single-direction header in the conventional micro-channel heat exchanger into a single annular closed header (first header), and the overall space height of the annular first header will be about 2 times less than the vertical single-direction header in the case of the same total number of flow paths of the micro-channel flat tubes, i.e. the vertical direction will overcome about 2 times gravity effect. The annular first header can make the refrigerant evenly distributed in the heat exchanger, improve the heat exchange efficiency, and due to the design of the annular header, the refrigerant can flow evenly in the first annular flow channel and be distributed to each flat tube, ensuring that each heat exchange unit can obtain appropriate refrigerant flow, thereby realizing uniform heat exchange, so that the design of the annular first header can adapt to both refrigeration and heating modes, whether as a condenser or an evaporator, can ensure the uniform distribution and flow of the refrigerant, and improve the adaptability and reliability of the heat exchanger. And the cooperation of the first header and the first flow guide pipe can make the refrigerant evenly distributed in the heat exchanger, improve the heat exchange efficiency, and through the annular flow channel of the first header and the bent flow guide channel of the first flow guide pipe, the refrigerant can evenly enter each flat tube, thereby improving the heat exchange efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the following embodiment or prior art description will be briefly introduced. Obviously, the drawings in the following description are only exemplary, and those skilled in the art can also obtain other implementation drawings according to the provided drawings without creative labor.

[0025] Figure 1 is a schematic view of the heat exchanger of the embodiment of the present application;

[0026] Figure 2 is an isometric view of the first header of the embodiment of the present application;

[0027] Figure 3 is another isometric view of the first header of the embodiment of the present application;

[0028] Figure 4 is a schematic view of the first flow guide pipe of the embodiment of the present application;

[0029] Figure 5 is a schematic view of the connection of the first flow guide pipe and the first header of the embodiment of the present application;

[0030] Figure 6 is an isometric view of the second header of the embodiment of the present application;

[0031] Figure 7 is another isometric view of the second header of the embodiment of the present application;

[0032] Figure 8 A first isometric view of a second draft tube according to an embodiment of the application;

[0033] Figure 9 A second isometric view of a second draft tube according to an embodiment of the application;

[0034] Figure 10 A third isometric view of a second draft tube according to an embodiment of the application;

[0035] Figure 11 A view of a second draft tube connected to a second collector according to an embodiment of the application;

[0036] Figure 12 A first isometric view of a second embodiment of a first draft tube according to an embodiment of the application;

[0037] Figure 13 A second isometric view of a second embodiment of a first draft tube according to an embodiment of the application;

[0038] Figure 14 A view of a second embodiment of a first draft tube connected to a first collector according to an embodiment of the application;

[0039] Figure 15 A view of a second embodiment of a heat exchanger according to an embodiment of the application;

[0040] Figure 16 A view of a fin according to an embodiment of the application;

[0041] Figure 17 A second view of a fin according to an embodiment of the application;

[0042] Figure 18 A view of an angle a according to an embodiment of the application.

[0043] Fig. 1 - first manifold; 11 - first annular flow channel; 12 - first end face of the first manifold; 101 - manifold body; 111 - first end head; 112 - second end head; 113 - first communication hole; 114 - second communication hole; 115 - mounting through hole; 102 - connecting pipe body; 121 - connecting flow channel; 103 - first connecting hole; 2 - first flow guide pipe; 3 - flow guide pipe body; 31 - first end of the flow guide pipe body; 32 - second end of the flow guide pipe body; 4 - elbow pipe; 41 - first end of the elbow pipe; 42 - second end of the elbow pipe; 43 - bent flow guide channel; 44 - first branch flow channel; 45 - second branch flow channel; 401 - first pipe section; 402 - second pipe section; 403 - first branch pipe section; 404 - second branch pipe section; 5 - second manifold; 51 - second annular flow channel; 52 - first region; 53 - second region; 501 - second connecting hole; 502 - flow guide connecting hole; 6 - second flow guide pipe; 61 - first end of the second flow guide pipe; 62 - second end of the second flow guide pipe; 63 - straight-through flow guide channel; 601 - flow guide through hole; 7 - microchannel flat tube; 8 - fin; 801 - clamping groove; 9 - spoiler. DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. The following description of at least one exemplary embodiment is merely illustrative in nature and not intended to be limiting on the present application and its applications or uses. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of the present application.

[0045] In the description of the present application, it should be understood that the orientation words such as "front, back, up, down, left, right", "transverse, vertical, perpendicular, horizontal" and "top, bottom" and the like indicate the orientation or position relationship shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate and imply that the indicated device or element must have a particular orientation or be constructed and operated in a particular orientation, therefore it cannot be understood as a limitation on the scope of protection of the present application; the orientation words "inner, outer" refer to the inner and outer relative to the contour of each component itself.

[0046] For purposes of the description hereinafter, spatial relative terms, such as "above", "below", "upper", "lower", and the like, can be used to describe the relative position of one element or feature to another element or feature as illustrated in the figures. It will be understood that the spatial relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientations depicted in the figures. For example, if the device in the figures is turned over, elements described as "above" or "up" other elements or features would then be oriented "below" or "down" the other elements or features. Thus, the exemplary term "above" can encompass both an orientation of above and below. The device can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatial relative terms used herein interpreted accordingly.

[0047] In addition, it should be noted that the use of "first", "second", and the like words of distinction do not connote any meaning of importance, but are used only to distinguish one element from another. Thus, the use of "first", "second", and the like words of distinction does not connote any meaning of importance, and should not be construed as limiting the scope of the present application.

[0048] With reference to the accompanying drawings, which are incorporated herein by reference, wherein: Figures 1 to 5 As shown, according to an embodiment of the present application, a fluid distribution structure is provided, which includes a first header 1 and a first flow guide 2. The first header 1 is annular, and along the circumference of the first header 1, the inner cavity of the first header 1 forms a first annular flow channel 11. A plurality of first connecting holes 103 are provided on the first end face 12 of the first header 1, and the first connecting holes 103 are used to connect with the flat tubes. The first flow guide 2 includes a flow guide body 3 and an elbow 4 connected with each other. The first end 31 of the flow guide body 3 extends out of the first header 1. The second end 32 of the flow guide body 3 and the first end 41 of the elbow 4 communicate with each other. The inner cavities of the flow guide body 3 and the elbow 4 form a bent flow guide channel 43. The second end 42 of the elbow 4 is connected with or provided in the first header 1. The bent flow guide channel 43 communicates with the first annular flow channel 11.

[0049] Specifically, the refrigerant flows into the flow guide body 3 from the first end 31 of the flow guide body 3, and then flows into the elbow 4 from the first end 41 of the elbow 4, that is, the refrigerant flows in the bent flow guide channel 43. After the refrigerant flows out of the second end 42 of the elbow 4, it flows into the first header 1. Since the inner cavity of the first header 1 forms the first annular flow channel 11, the refrigerant flows in the first annular flow channel 11 and is distributed to each flat tube.

[0050] Specifically, when the fluid distribution structure is applied to the heat exchanger, during refrigeration, the heat exchanger acts as a condenser, and the refrigerant first exchanges heat in the flat tube and then flows into the first header 1, and then flows through the flow guide pipe body 3 and the elbow pipe 4, and then enters the next process. During heating, the entire heat exchanger acts as an evaporator, and the flow direction of the entire refrigerant is opposite to that when the heat exchanger acts as a condenser. The throttled gas-liquid two-phase refrigerant flows into the flow guide pipe body 3 from the first end 31 of the flow guide pipe body 3, then flows into the elbow pipe 4, that is, the gas-liquid two-phase refrigerant flows in the bent flow guide 43, and then flows into the first header 1 from the second end 42 of the elbow pipe 4, and then circulates in the first annular flow channel 11. During this process, the gas-liquid two-phase refrigerant enters the flat tube, and the refrigerant evaporates and exchanges heat in the micro-channel flat tube 7. The refrigerant vapor flows out of the flat tube and enters the next process after completing the evaporation and heat exchange.

[0051] In this embodiment, the vertical one-way header in the conventional micro-channel heat exchanger is improved to a single annular closed header (first header 1). Under the condition that the total number of micro-channel flat tube 7 flow paths remains unchanged, the overall space height of the annular first header 1 will be about 2 times less than that of the vertical one-way header, that is, the vertical direction will overcome about 2 times less gravity. The annular first header 1 can uniformly distribute the refrigerant in the heat exchanger and improve the heat exchange efficiency. Due to the design of the annular header, the refrigerant can flow uniformly in the first annular flow channel 11 and be distributed to each flat tube, ensuring that each heat exchange unit can obtain appropriate refrigerant flow, thereby achieving uniform heat exchange. The design of the annular first header 1 can adapt to both refrigeration and heating modes, whether it acts as a condenser or an evaporator, it can ensure uniform distribution and flow of the refrigerant, improving the adaptability and reliability of the heat exchanger. The cooperation of the first header 1 and the first flow guide pipe 2 can make the refrigerant uniformly distributed in the heat exchanger and improve the heat exchange efficiency. Through the annular flow channel of the first header 1 and the bent flow guide 43 of the first flow guide pipe 2, the refrigerant can uniformly enter each flat tube, thereby improving the heat exchange efficiency.

[0052] Furthermore, the first guide pipe 2 includes a bend 4. The bend 4 changes the flow direction of the fluid, allowing the fluid to flow in from the guide pipe body 3, change direction after passing through the bend 4, and then flow into the first manifold 1. This change in flow direction helps to achieve uniform distribution and mixing of the fluid in the heat exchanger, thereby improving heat exchange efficiency. The bend 4 reduces resistance during fluid flow. Compared to right-angle turns, the bend 4 can guide the fluid to change direction more smoothly, reducing energy loss and pressure drop caused by right-angle turns. The first guide pipe 2 is installed at the refrigerant inlet of the first manifold 1, meaning the refrigerant's velocity direction is angled to the first manifold 1 at this point. This reduces the reflection effect of the refrigerant directly impacting the wall, allowing the refrigerant to circulate within the annular first manifold 1. Utilizing the refrigerant's initial velocity to overcome less gravitational influence, the refrigerant circulates within the annular manifold, reducing pressure drop, achieving uniform flow distribution, and enhancing heat exchanger performance. Furthermore, the bend 4 allows the refrigerant to flow in the bend guide channel 43 before entering the annular manifold, which helps to mix the gas and liquid refrigerant. This allows the refrigerant to enter the heat exchange tube in a more uniform mist form, improving heat exchange efficiency. In the design of air conditioning heat exchangers, the bend 4 can adapt to different spatial layout requirements, allowing the pipeline to be flexibly arranged in a limited space while meeting the structural and performance requirements of the heat exchanger.

[0053] It is worth noting that, in this embodiment, in conjunction with the reference... Figure 18 As shown, the first manifold 1 is provided with a mounting through hole 115 for installing the first guide pipe 2. The central axis of the bend 4's opening and the central axis of the mounting through hole 115 form an angle α, which ranges from 10° to 30°. In this embodiment, the bend 4 is used to create an angle α between the refrigerant's velocity direction and the inner wall of the first manifold 1. In other embodiments, this angle can also be achieved by changing the refrigerant inlet opening angle of the first manifold 1.

[0054] See also Figures 1 to 5 As shown, the bend 4 is L-shaped. In the axial direction of the guide tube body 3, the second end 42 of the bend 4 is bent in the first direction, and the first end 41 of the bend 4 is connected to the first collector tube 1.

[0055] Specifically, the refrigerant first flows into the first end 31 of the flow guide pipe body 3, at this time, the refrigerant flows along the axial direction of the flow guide pipe body 3, when the refrigerant reaches the second end 32 of the flow guide pipe body 3, due to the L-shaped design of the elbow pipe 4, the flow direction of the refrigerant changes, so that the refrigerant bends in the first direction at the second end 42 of the elbow pipe 4, thereby realizing the adjustment of the flow direction, the refrigerant then flows into the elbow pipe 4 and continues to flow along the bent flow guide channel 43 of the elbow pipe 4. After the refrigerant flows out of the second end 42 of the elbow pipe 4, it flows into the first header 1, and due to the formation of the first annular flow channel 11 in the inner cavity of the first header 1, the refrigerant flows in the first annular flow channel 11 and is distributed to each flat tube. In the refrigeration mode, the refrigerant flows into the first header 1 after heat exchange in the flat tube, sequentially flows through the flow guide pipe body 3 and the elbow pipe 4, and then enters the next flow process. In the heating mode, the flow direction of the entire refrigerant is opposite to that in the refrigeration mode, the throttled gas-liquid two-phase refrigerant flows in the bent flow guide channel 43, then flows into the first header 1 from the second end 42 of the elbow pipe 4, and circulates in the first annular flow channel 11, in this process, the gas-liquid two-phase refrigerant enters the flat tube to complete the evaporation heat exchange.

[0056] In the present embodiment, the L-shaped elbow pipe 4 helps to reduce the pressure drop in the refrigerant flow process, by changing the flow direction, the L-shaped elbow pipe 4 can reduce the reflection effect of the refrigerant directly impacting the wall surface, which helps the refrigerant to circulate in the annular first header 1, and utilizes the initial speed of the refrigerant to reduce the pressure drop and complete uniform distribution under the condition of overcoming less gravity effect.

[0057] It is worth noting that, in the orientation shown in the figure, the first direction is to the right relative to the axial direction of the flow guide pipe body 3, at this time, the refrigerant flows counterclockwise in the first header 1, in other embodiments, if the refrigerant flows clockwise in the first header 1, in order to facilitate the distribution of the refrigerant, the second end 42 of the elbow pipe 4 is reversely arranged. The turning angle of the elbow is in the range of 70° to 90°, and a reasonable turning angle can also be given according to the actual situation.

[0058] For reference Figures 1 to 5 As shown in the figure, the elbow pipe 4 includes a first pipe segment 401 and a second pipe segment 402 in communication with each other, the first pipe segment 401 is in communication with the flow guide pipe body 3 away from one end of the second pipe segment 402, the second pipe segment 402 is a necked structure, and the second pipe segment 402 extends into the first header 1 away from one end of the first pipe segment 401.

[0059] In the embodiment, the specific bending of the bend pipe 4 is achieved by bending the first pipe section 401, and the second pipe section 402 is the bent pipe section. The necking structure can reduce the resistance in the fluid flow process, especially when the fluid passes through the bend pipe 4. The necking can increase the fluid flow rate, thereby reducing the pressure drop. At the necking, the fluid flow rate increases, and according to the continuity equation and Bernoulli equation, the increase of the flow rate will cause the local pressure to decrease, which helps to throttle the refrigerant. Moreover, the necking structure can reduce the situation that the fluid directly impacts the wall surface of the bend pipe 4, and reduce the reflection and vibration caused thereby. In other embodiments, the necking structure can be changed in size to adapt to different flow requirements, thereby providing certain flow regulation capacity for the system.

[0060] As a specific embodiment, the diameter of the second pipe section 402 in the necking structure is between 1 / 2 and 3 / 4 of the diameter of the flow guide pipe body 3. A reasonable necking diameter can also be given according to the actual situation.

[0061] For reference Figures 1 to 5 As shown in the drawings, the first header 1 includes a header body 101 and a connecting pipe body 102. The header body 101 has a first end head 111 and a second end head 112 which are away from each other. The first end head 111 and the second end head 112 are closed. The first end head 111 is provided with a first communication hole 113, and the second end head 112 is provided with a second communication hole 114. The two ends of the connecting pipe body 102 are connected with the first communication hole 113 and the communication hole respectively, and the inner cavity of the connecting pipe body 102 forms a connecting flow channel 121. The connecting flow channel 121 is communicated with the first annular flow channel 11, and the second end 42 of the bend pipe 4 is connected with the first end head 111.

[0062] Specifically, the connecting pipe body 102 is arc-shaped, and the first flow guide pipe 2 is L-shaped. The refrigerant first flows into the first end 31 of the flow guide pipe body 3, at this time, the refrigerant flows along the axis direction of the flow guide pipe body 3. When the refrigerant reaches the second end 32 of the flow guide pipe body 3, due to the L-shaped design of the elbow pipe 4, the flow direction of the refrigerant changes, so that the refrigerant bends in the first direction at the second end 42 of the elbow pipe 4, thereby realizing the adjustment of the flow direction. The refrigerant then flows into the elbow pipe 4 and continues to flow along the bent flow guide channel 43 of the elbow pipe 4. After the refrigerant flows out of the second end 42 of the elbow pipe 4, it flows into the first header pipe 1. Since the inner cavity of the first header pipe 1 forms a first annular flow channel 11, the refrigerant flows in the first annular flow channel 11 and is distributed to each flat tube. Part of the refrigerant that is not distributed to the flat tube continues to flow into the connecting pipe body 102, flows in the connecting flow channel 121, and then flows into the header pipe body 101 again to mix with the refrigerant flowing out of the elbow pipe 4 and be distributed again. In the cooling mode, the refrigerant flows into the first header pipe 1 after heat exchange in the flat tube, sequentially flows through the flow guide pipe body 3 and the elbow pipe 4, and then enters the next flow process. In the heating mode, the flow direction of the entire refrigerant is opposite to that in the cooling mode. The throttled gas-liquid two-phase refrigerant flows in the bent flow guide channel 43, then flows into the first header pipe 1 from the second end 42 of the elbow pipe 4, and circulates in the first annular flow channel 11. In this process, the gas-liquid two-phase refrigerant enters the flat tube to complete the evaporation heat exchange, and the refrigerant that is not distributed flows into the connecting pipe body 102 and then flows into the first header pipe 1 to circulate.

[0063] In this embodiment, the refrigerant flows counterclockwise in the first header pipe 1, the elbow pipe 4 bends to the right, and the refrigerant also flows counterclockwise in the connecting pipe body 102. Through the design of the first header pipe 1 and the connecting pipe body 102, the refrigerant can be more evenly distributed to each flat tube, improving the heat exchange efficiency. The refrigerant that is not distributed to the flat tube flows into the connecting pipe body 102, then flows into the header pipe body 101 again to mix with the refrigerant flowing out of the elbow pipe 4, realizing the circulation of the refrigerant. This helps to further evenly distribute and improve the heat exchange efficiency. Moreover, by reducing the dead zones and short circuits in the flow of the refrigerant, the energy loss is reduced, and the overall performance of the system is improved. The design of the connecting pipe body 102 helps to more evenly distribute the refrigerant to each flat tube or flow channel, reduces the difference in heat exchange efficiency caused by uneven distribution, and the circulation after the connecting pipe body 102 is set reduces the dead corners and stagnant areas of the refrigerant in the system, reduces the risk of system failure caused by local overheating or uneven cooling, and improves the reliability of the entire system.

[0064] It is worth mentioning that in the present embodiment, when the first header 1 comprises the header body 101 and the connecting pipe body 102, the first flow guide pipe 2 is preferably in the L shape, which is considered to form a circulating flow when the refrigerant flows counterclockwise in the first header 1.

[0065] As a specific embodiment, the flow guide pipe body 3 is provided with a spoiler 9, which generates a non-stable flow state such as turbulence or vortex by changing the fluid flow direction and increasing the instability of the fluid flow, thereby increasing the energy loss and resistance of the fluid, which helps to improve the heat exchange efficiency. The spoiler 9 can make the fluid flow in a spiral state in the heat exchanger, enhance the disturbance in the pipe, strengthen the heat exchange, and greatly improve the heat exchange coefficient. The spoiler 9 can play a role for both laminar flow and turbulent flow, and achieve the purpose of mixed disturbance through different flow characteristics.

[0066] As a specific embodiment, the first end 111 is provided with a mounting through hole 115 for mounting the first flow guide pipe 2, and the first communication hole 113 is located radially inside the mounting through hole 115. This arrangement facilitates the flow of refrigerant in the first flow guide pipe 2 out of the first flow guide pipe 2 without affecting the flow of refrigerant in the connecting pipe body 102.

[0067] For reference Figures 1 to 11 As shown in the figure, it also includes a second header 5 and a second flow guide pipe 6. The second header 5 is annular, and along the circumference of the second header 5, the inner cavity of the second header 5 forms a second annular flow channel 51. A plurality of second connecting holes 501 are provided on the first end face of the second header 5, and the second connecting holes 501 are used to connect with the flat tubes. The first header 1 and the second header 5 are respectively arranged at both ends of the flat tube. The first end 61 of the second flow guide pipe 6 extends out of the second header 5, and the second end 62 of the second flow guide pipe 6 is connected with the second header 5.

[0068] Specifically, during refrigeration, the heat exchanger acts as a condenser. High-temperature and high-pressure refrigerant vapor from the outlet of the compressor flows into the second header 5 from the second flow guide pipe 6 and is divided in the second header 5. The refrigerant vapor enters all the micro-channel flat tubes 7. At this time, the refrigerant vapor in the micro-channel flat tubes 7 has begun to exchange heat with the outside and condense. After all the micro-channel flat tubes 7 complete condensation, the refrigerant liquid enters the first header 1, gathers together, and then flows through the first flow guide pipe 2 and the spoiler 9 in turn. After exiting the spoiler 9, it enters the next process.

[0069] Specifically, when heating, the heat exchanger acts as an evaporator, the flow direction of the entire refrigerant is opposite to that when the heat exchanger acts as a condenser, the throttled gas-liquid two-phase refrigerant enters the turbulence chamber from the turbulence inlet 9, and the gas-liquid mixed refrigerant after turbulence is uniformly mixed. The refrigerant flows into the first flow guide pipe 2 and then into the first header 1, and circulates therein. In this process, the gas-liquid two-phase refrigerant enters the micro-channel flat tube 7, the refrigerant evaporates and exchanges heat in the micro-channel flat tube 7, the refrigerant vapor after completing the evaporation and heat exchange is collected into the second header 5, and finally enters the next process through the second flow guide pipe 6.

[0070] In the embodiment, the refrigerant can be more uniformly distributed to each micro-channel flat tube 7 through the cooperation of the headers and the flow guide pipes, and the heat exchange efficiency is improved. In the refrigeration mode, the heat exchanger acts as a condenser, and the high-temperature and high-pressure refrigerant vapor is distributed into the micro-channel flat tube 7 to condense in the second header 5. In the heating mode, the heat exchanger acts as an evaporator, and the gas-liquid two-phase refrigerant circulates and evaporates in the first header 1. This design makes the heat exchanger adapt to different working modes. The first header 1 and the second header 5 are both arranged in a ring shape, which helps to achieve uniform distribution of the fluid in the heat exchanger. This design can ensure that the refrigerant is uniformly distributed before entering the micro-channel flat tube 7, thereby improving the heat exchange efficiency. In the refrigeration and heating modes, the ring-shaped header can adapt to the change of the flow direction of the heat exchanger as a condenser and an evaporator, and ensure the uniform distribution and flow of the refrigerant.

[0071] As a specific embodiment, the cross-sectional shape of the first header 1 and the second header 5 is irregular, specifically, the cross-section includes a rectangular segment and a circular arc segment, and the end face of the first header 1 and the second header 5 for mounting the flat tube is a plane. The plane in this embodiment is arranged so that the flat tube can not be inserted for a long distance and can utilize limited area for heat exchange. In a conventional circular cross-section header, the flat tube is usually installed in the header for a long distance in order to install the flat tube.

[0072] For reference Figures 1 to 11 As shown in FIG. 6, the second end 62 of the second flow guide pipe 6 is closed and extends into the second header 5. The inner cavity of the second flow guide pipe 6 has a straight flow guide channel 63, and the outer wall of the second end 62 of the second flow guide pipe 6 is provided with a flow guide through hole 601. The straight flow guide channel 63 communicates with the second annular flow channel 51 through the flow guide through hole 601, and the flow guide through hole 601 is used for discharging and absorbing the refrigerant vapor.

[0073] Specifically, during refrigeration, the refrigerant first flows out of the high-temperature and high-pressure vapor state from the compressor discharge port into the second flow guide pipe 6. The refrigerant flows into the second manifold 5 through the straight-through flow guide channel 63 of the second flow guide pipe 6 and is divided in the second manifold 5. Since the second end 62 of the second flow guide pipe 6 extends into the second manifold 5, and the outer wall of the second end is provided with flow guide through holes 601, the refrigerant flows from the straight-through flow guide channel 63 into the second annular flow channel 51 through the flow guide through holes 601. The divided refrigerant vapor enters all the micro-channel flat tubes 7 and starts heat exchange with the outside world to condense. The refrigerant liquid after completing condensation in all the micro-channel flat tubes 7 enters the first manifold 1 and converges together. The refrigerant liquid converged in the first manifold 1 flows through the first flow guide pipe 2 and the flow disturber 9 in turn, and enters the next process after flowing out of the flow disturber 9.

[0074] In the present embodiment, although the refrigerant can flow into the first flow guide pipe 2 or the second flow guide pipe 6 by reversing, the refrigerant flowing into the second flow guide pipe 6 is always gaseous refrigerant, while the refrigerant flowing into the first flow guide pipe 2 is always two-phase refrigerant, and the proportion of liquid refrigerant is large. Therefore, the structures of the first flow guide pipe 2 and the second flow guide pipe 6 are different. The flow guide through holes 601 of the second flow guide pipe 6 are connected with the annular flow channel of the second manifold 5, which can realize more uniform distribution of the refrigerant, reduce the erosion of the fluid medium to the heat exchange pipe, and strengthen the heat transfer performance. In the place where the flat tube is not arranged, the first manifold 1 uses an arc-shaped connecting pipe body to connect. Here, the arc-shaped pipe connection is adopted, which can save materials, and form a structure of sudden contraction and sudden expansion from the first end 111 to the second end 112, which has the effect of flow guiding. This effect helps the division of two-phase flow and completes the circulation during heating.

[0075] For reference Figures 1 to 11 As shown in the figure, the outer wall of the second end 62 of the second flow guide pipe 6 is provided with at least two flow guide through holes 601. The first flow guide through hole 601 and the second flow guide through hole 601 are oppositely arranged to form a first division channel and a second division channel between the straight-through flow guide channel 63 and the second annular flow channel 51.

[0076] In the embodiment, two flow guide through holes 601 are arranged on each side, two first flow guide through holes 601 and two second flow guide through holes 601 are arranged on the circumferential wall at different angles in the circumferential direction of the second flow guide pipe 6. The high-temperature and high-pressure steam state of the refrigerant first discharged from the compressor flows into the straight flow guide channel 63 of the second flow guide pipe 6. The refrigerant flows into the second flow collecting pipe 5 through the straight flow guide channel 63 of the second flow guide pipe 6 and is branched in the second flow collecting pipe 5. Since the outer wall of the second end 62 of the second flow guide pipe 6 is provided with at least two flow guide through holes 601, the first flow guide through hole 601 and the second flow guide through hole 601 are oppositely arranged. The refrigerant flows into the second annular flow channel 51 from the straight flow guide channel 63 through the flow guide through holes 601, forming a first branch channel and a second branch channel. The branched refrigerant vapor enters all the micro-channel flat tubes 7 and starts heat exchange with the outside world to condense. In the embodiment, two opposite flow guide through holes 601 are arranged on the outer wall of the second end 62 of the second flow guide pipe 6. The first branch channel and the second branch channel are formed between the straight flow guide channel 63 and the second annular flow channel 51, so that the refrigerant is more evenly distributed.

[0077] For reference Figures 1 to 11 As shown in the figure, along the circumferential direction of the second flow collecting pipe 5, the first end face of the second flow collecting pipe 5 has a first region 52 and a second region 53. A plurality of second connecting holes 501 are arranged in the first region 52, and the second region 53 is a non-hole region. The outer circumferential wall of the second flow collecting pipe 5 is provided with a flow guide connecting hole 502. The second end 62 of the second flow guide pipe 6 penetrates into the second flow collecting pipe 5 through the flow guide connecting hole 502. The flow guide through hole 601 is correspondingly arranged with the second region 53, and the distance from the flow guide connecting hole to the two ends of the second connecting hole 501 is equal.

[0078] In the embodiment, the second region 53 occupies an angle of the central angle of the circle > 90° as the projection plane of the cross section of the second flow collecting pipe 5. Under the influence of gravity, liquid accumulation is inevitable in this region. The second region 53 is not provided with holes to avoid liquid accumulation in this region and reduce the flow resistance caused by liquid accumulation. In addition, the non-hole region can help to concentrate the flow direction, so that the refrigerant passes through the first region 52 with holes more evenly, thereby improving the heat exchange efficiency.

[0079] It is worth noting that the second region 53 is not provided with holes, and the corresponding region of the first flow collecting pipe 1 is also not provided with holes for mounting the flat tube. The corresponding first flow collecting pipe 1 is provided with a connecting pipe body 102 at this position. In this way, the first flow collecting pipe 1 and the second flow collecting pipe 5 are not provided with corresponding flat tube mounting holes.

[0080] For reference Figures 1 to 15 As another embodiment, the elbow pipe 4 is a bifurcated structure, and the elbow pipe 4 is arranged in the first flow collecting pipe 1.

[0081] Specifically, the refrigerant first flows into the first end 31 of the flow guide pipe body 3, flows along the axial direction of the flow guide pipe body 3, and when the refrigerant reaches the second end 32 of the flow guide pipe body 3, when the refrigerant reaches the connection between the flow guide pipe body 3 and the elbow pipe 4, due to the bifurcated structure of the elbow pipe 4, the refrigerant is divided into two or more channels, and the bifurcated refrigerant flow paths enter different areas of the first header 1, respectively. After the refrigerant flows out of the second end 42 of the elbow pipe 4, it flows into the first header 1. Since the inner cavity of the first header 1 forms a first annular flow channel 11, the refrigerant flows in the first annular flow channel 11 and is distributed to each flat tube.

[0082] In this embodiment, the bifurcated structure of the elbow pipe 4 can more evenly distribute the refrigerant to multiple flow channels, and the bifurcated structure can reduce the local resistance during the flow of the refrigerant, thereby reducing the pressure drop of the entire system, improving the energy efficiency of the system, and compared with a complex distribution structure, the bifurcated structure is generally simpler, which helps to simplify the manufacturing process and reduce maintenance costs, and the bifurcated structure can more effectively utilize the internal space of the heat exchanger, especially in space-limited applications. In addition, the bifurcated structure can be adjusted flexibly, and the number and angle of bifurcation can be adjusted according to the specific application requirements to achieve the best distribution effect.

[0083] For reference Figures 1 to 15 As shown, the elbow pipe 4 includes a first branch pipe section 403 and a second branch pipe section 404, one end of each of the first branch pipe section 403 and the second branch pipe section 404 communicates with the flow guide pipe body 3, in the axial direction of the flow guide pipe body 3, the other end of the first branch pipe section 403 is bent in a first direction, and the other end of the second branch pipe section 404 is bent in a second direction, the first branch pipe section 403 and the flow guide pipe body 3 form a first branch flow channel 44, and the second branch pipe section 404 and the flow guide pipe body 3 form a second branch flow channel 45.

[0084] Specifically, the refrigerant first flows into the first end 31 of the flow guide pipe body 3, flows along the axial direction of the flow guide pipe body 3, and when the refrigerant reaches the connection between the flow guide pipe body 3 and the elbow pipe 4, due to the bifurcated structure of the elbow pipe 4, the refrigerant is divided into two or more channels, and the bifurcated refrigerant flow paths enter different areas of the first header 1, respectively. After the refrigerant flows out of the second end 42 of the elbow pipe 4, it flows into the first header 1. Since the inner cavity of the first header 1 forms a first annular flow channel 11, the refrigerant flows in the first annular flow channel 11 and is distributed to each flat tube.

[0085] In the embodiment, the first direction is right, the second direction is left, the design of the two branch flow channels can make the refrigerant more evenly distributed in the first header 1, reduce gas-liquid phase separation, improve the uniformity of the distribution, by reasonably designing the bending angle, bending radius and pipe diameter of the branch pipe section, the structure of the distributor connecting pipe can be optimized, and the problem of uneven distribution can be reduced. The reason why the two branch flow channels can be realized in the embodiment is that the entire elbow pipe 4 is arranged in the first header 1, so that even if the elbow pipe 4 is bifurcated, the conversion of the refrigerant flow direction can be realized, the reflection effect of the refrigerant directly impacting the wall surface is reduced, the refrigerant circulates in the annular first header 1, and the initial speed of the refrigerant is used to overcome the influence of gravity, so that the refrigerant circulates in the annular first header 1, the pressure drop is reduced, the uniform distribution is completed, and the performance of the heat exchanger is enhanced.

[0086] As a specific embodiment, when the elbow pipe 4 is a bifurcated structure, the turning angle of the one-way elbow is in the range of 70° to 90°, and a reasonable turning angle can also be given according to the actual situation. The pipe opening of the branch pipe section of the elbow is a necked structure, and the necked structure is used to enhance the speed of the two-phase mixed flow during heating. The necked range is related to the flow rate of the refrigerant in the system. Here, the diameter of the neck is between 1 / 2 and 3 / 4 of the diameter of the flow guide pipe body 3. A reasonable neck diameter can also be given according to the actual situation. The first header 1 and the second header 5 are complete annular, but in order to avoid the existence of dead angle in the header, the header is still not provided with a hole for installing the flat tube at the position corresponding to the installation of the flow guide pipe. Compared with the elbow pipe 4 of the one-way elbow, the maximum flow path of the refrigerant of the bifurcated structure of the distribution elbow is halved, which is beneficial to reduce the distribution pressure drop and increase the distribution effect.

[0087] Referring to Figure 1 and Figure 15 , a heat exchanger includes a fluid distribution structure and a plurality of micro-channel flat tubes 7 and fins 8, characterized in that the fluid distribution structure is the fluid distribution structure described above, the plurality of micro-channel flat tubes 7 are arranged along the circumferential direction of the first header 1, and the plurality of fins 8 are arranged along the axial direction of the micro-channel flat tube 7.

[0088] In the embodiment, the cooperation of the micro-channel flat tube 7 and the fin 8 can significantly increase the heat exchange area, so that the heat transfer between the cold and hot fluids is more sufficient, thereby improving the heat transfer rate and overall efficiency of the heat exchanger. The shape and arrangement of the fin 8 can affect the flow state of the fluid in the tube, and reasonable design can reduce the flow resistance of the fluid, improve the fluid disturbance, promote the formation of turbulent flow of the fluid, and enhance the heat transfer effect. Since the first and second headers 1 and 5 are annular, the micro-channel flat tube 7 on the entire heat exchanger also presents an annular arrangement, which is quite different from the flat heat exchanger. The fin 8 used here is different from the ordinary flat fin 8. The micro-channel flat tube 7 and the annular fin 8 structure in this embodiment form many different angles with the horizontal plane in space. It is beneficial to drain water during defrosting and condensation, and can enhance the overall performance of the heat exchanger. The inner and outer diameters and the circumferential length of the fin 8 can be appropriately adjusted according to the actual needs of the heat exchanger.

[0089] For reference Figure 16 and Figure 17 As shown in FIGS. 1 to 3, the fin 8 is annular, and the inner diameter and the outer diameter of the fin 8 are smaller than the inner diameter and the outer diameter of the first header 1. Along the circumferential direction of the fin 8, a plurality of clamping grooves 801 are arranged on the fin 8, and the clamping grooves 801 are connected with the micro-channel heat exchange flat tube.

[0090] In the embodiment, the fin 8 unit is in the shape of a circular ring, and the inner diameter and the outer diameter are slightly smaller than the inner diameter and the outer diameter of the header, respectively, to protect and install the fin 8. The clamping groove 801 of the micro-channel flat tube 7 is arranged near the inner diameter, and the micro-channel flat tube 7 can be cooperated to realize heat conduction. In addition, impact holes are opened on the micro-channel fin 8 to separate adjacent fins 8 to form gaps. The introduction of the impact holes plays a role in disturbing the flow and enhancing the heat exchange to some extent. The fin 8 is annular and has a plurality of clamping grooves 801 connected with the micro-channel heat exchange flat tube, which can increase the heat exchange area and thus improve the heat exchange efficiency. The inner diameter and the outer diameter of the annular fin 8 are smaller than the inner diameter and the outer diameter of the first header 1, which provides good structural support and enhances the overall stability. The inner diameter and the outer diameter of the annular fin 8 are smaller than the inner diameter and the outer diameter of the first header 1, which provides good structural support and enhances the overall stability. After the structure of the fin 8 is combined with the structure of the header, the heat of the high-temperature fluid in the micro-channel flat tube 7 can be transferred to the fin 8 unit by heat conduction when the heat exchanger is used as a condenser during refrigeration. The fin 8 further removes heat through heat convection with air, achieving the purpose of cooling the high-temperature fluid in the micro-channel flat tube 7.

[0091] As a specific implementation, the clamping groove 801 can be upwardly or downwardly opened, so that the fin 8 is clamped from the outer peripheral side of the flat tube or from the inner peripheral side of the flat tube.

[0092] An outdoor unit includes a heat exchanger, and the heat exchanger is the heat exchanger described above.

[0093] An air conditioner comprises an outdoor unit, and the outdoor unit is the above-mentioned outdoor unit.

[0094] Those skilled in the art can easily understand that the above-mentioned advantageous modes can be freely combined and superimposed without conflict.

[0095] The above is only the preferred embodiment of the present application, and should be pointed out that, for ordinary skilled in the art, without departing from the technical principles of the present application, can also make a number of improvements and variations, these improvements and variations should be considered as the protection scope of the present application.

Claims

1. A fluid flow splitting structure, characterized by, The application relates to a refrigerant distribution device. The first collecting pipe (1) is annular, and a first annular flow channel (11) is formed in the inner cavity of the first collecting pipe (1) along the circumference of the first collecting pipe (1); a first end surface (12) of the first collecting pipe (1) is provided with a plurality of first connecting holes (103) for connecting with flat pipes. The first flow guide pipe (2) comprises a flow guide pipe body (3) and an elbow pipe (4) connected with each other; a first end (31) of the flow guide pipe body (3) extends out of the first collecting pipe (1); a second end (32) of the flow guide pipe body (3) and a first end (41) of the elbow pipe (4) are in communication with each other; the inner cavities of the flow guide pipe body (3) and the elbow pipe (4) form a bent flow guide channel (43); a second end (42) of the elbow pipe (4) is connected with or arranged in the first collecting pipe (1); the bent flow guide channel (43) is in communication with the first annular flow channel (11). The first collecting pipe (1) comprises a collecting pipe body (101) and a connecting pipe body (102); the collecting pipe body (101) has a first end head (111) and a second end head (112) which are away from each other; the first end head (111) and the second end head (112) are arranged in a closed mode; the first end head (111) is provided with a first communication hole (113); the second end head (112) is provided with a second communication hole (114); two ends of the connecting pipe body (102) are connected with the first communication hole (113) and the second communication hole (114) respectively; the inner cavity of the connecting pipe body (102) forms a connecting flow channel (121); the connecting flow channel (121) is in communication with the first annular flow channel (11); the second end (42) of the elbow pipe (4) is connected with the first end head (111); wherein refrigerant flows and is distributed in the first annular flow channel (11); undistributed refrigerant flows into the connecting pipe body (102) and then flows into the first annular flow channel (11) again. The elbow pipe (4) is L-shaped; in the axial direction of the flow guide pipe body (3), the second end (42) of the elbow pipe (4) is arranged in a first direction in a bent mode; and the second end (42) of the elbow pipe (4) is connected with the first collecting pipe (1).

2. The fluid flow splitting structure of claim 1, wherein, The elbow pipe (4) comprises a first pipe section (401) and a second pipe section (402) which are in communication with each other; one end of the first pipe section (401) which is away from the second pipe section (402) is in communication with the flow guide pipe body (3); the second pipe section (402) is in a necked structure; and one end of the second pipe section (402) which is away from the first pipe section (401) extends into the first collecting pipe (1).

3. The fluid flow splitting structure of claim 2, wherein, The elbow pipe (4) is in a bifurcated structure; and the elbow pipe (4) is arranged in the first collecting pipe (1).

4. The fluid flow structure of claim 1, wherein, ​ 5. The fluid flow structure of claim 4, wherein, The elbow pipe (4) comprises a first branch pipe section (403) and a second branch pipe section (404), one end of the first branch pipe section (403) and the second branch pipe section (404) communicates with the flow guide pipe body (3), in the axial direction of the flow guide pipe body (3), the other end of the first branch pipe section (403) is arranged in a first direction, the other end of the second branch pipe section (404) is arranged in a second direction, the first branch pipe section (403) and the flow guide pipe body (3) form a first branch flow passage (44), and the second branch pipe section (404) and the flow guide pipe body (3) form a second branch flow passage (45).

6. The fluid flow structure according to any one of claims 1 to 5, wherein, The second manifold (5) is annular, and the inner cavity of the second manifold (5) forms a second annular flow passage (51) along the circumference of the second manifold (5), a plurality of second connecting holes (501) are arranged on the first end face of the second manifold (5), the second connecting holes (501) are used for being connected with flat pipes, and the first manifold (1) and the second manifold (5) are arranged at two ends of the flat pipe respectively; the first end (61) of the second flow guide pipe (6) protrudes out of the second manifold (5), and the second end (62) of the second flow guide pipe (6) is connected with the second manifold (5).

7. The fluid flow structure of claim 6, wherein, The second end (62) of the second flow guide pipe (6) is arranged in a closed mode, the second end (62) of the second flow guide pipe (6) protrudes into the second manifold (5), the inner cavity of the second flow guide pipe (6) has a straight-through flow guide passage (63), the outer wall of the second end (62) of the second flow guide pipe (6) is provided with a flow guide through hole (601), and the straight-through flow guide passage (63) communicates with the second annular flow passage (51) through the flow guide through hole (601).

8. The fluid flow structure of claim 7, wherein, The outer wall of the second end (62) of the second flow guide pipe (6) is provided with at least two flow guide through holes (601), the first flow guide through hole (601) and the second flow guide through hole (601) are arranged oppositely, so that the first branch flow passage and the second branch flow passage are formed between the straight-through flow guide passage (63) and the second annular flow passage (51).

9. The fluid flow structure of claim 7, wherein, Along the circumference of the second manifold (5), the first end face of the second manifold (5) has a first region (52) and a second region (53), a plurality of second connecting holes (501) are arranged in the first region (52), and the second region (53) is a non-hole region; the outer circumferential wall of the second manifold (5) is provided with a flow guide connecting hole (502), the second end (62) of the second flow guide pipe (6) protrudes into the second manifold (5) through the flow guide connecting hole (502), and the flow guide through hole (601) is arranged correspondingly to the second region (53).

10. A heat exchanger comprising a fluid distribution structure and a plurality of microchannel flat tubes (7) and fins (8), characterized in that, The fluid distribution structure is the fluid distribution structure according to any one of claims 1 to 9, a plurality of the micro-channel flat tubes (7) are arranged along the circumference of the first header (1), and a plurality of the fins (8) are arranged along the axial direction of the micro-channel flat tube (7).

11. The heat exchanger of claim 10, wherein The fin (8) is annular, the inner diameter of the fin (8) is smaller than the inner diameter of the first header (1), the outer diameter of the fin (8) is smaller than the outer diameter of the first header (1), and a plurality of clamping grooves (801) are arranged on the fin (8) along the circumferential direction of the fin (8), and the clamping grooves (801) are connected with the micro-channel flat tube (7).

12. An outdoor unit comprising a heat exchanger, characterized by, The heat exchanger is the heat exchanger according to claim 10 or claim 11.

13. An air conditioner comprising an outdoor unit, characterized by comprising: The outdoor unit is the outdoor unit according to claim 12.

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