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

Abstract

The invention provides a fluid flow dividing structure, a heat exchanger, an outdoor unit and an air conditioner. The fluid flow dividing structure comprises a first flow collecting pipe and a first flow guiding pipe. The first collecting pipe is annular, an inner cavity of the first collecting pipe forms a first annular flow channel, a plurality of first connecting holes are formed in the first end face of the first collecting pipe, and the first connecting holes are used for being connected with flat pipes; the first flow guide pipe comprises a flow guide pipe body and a bent 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 is communicated with the first end of the bent pipe, inner cavities of the flow guide pipe body and the bent pipe form a bent flow guide channel, and the second end of the bent pipe is connected with the first collecting pipe or arranged in the first collecting pipe. And the bent flow guide channel is communicated with the first annular flow channel. According to the heat exchanger, refrigerants can be evenly distributed in the heat exchanger through the annularly-arranged first flow collecting pipes, the heat exchange efficiency is improved, and the resistance in the fluid flowing process can be reduced through the arrangement of the bent pipes.

Description

Technical Field

[0001] The present invention belongs to the technical field of air conditioners, and in particular relates to a fluid flow splitting structure, a heat exchanger, an outdoor unit and an air conditioner. Background Art

[0002] Air conditioners can provide a strong guarantee for a comfortable living environment. Their heat exchangers mainly include fin-tube heat exchangers and microchannel heat exchangers. Compared with fin-tube heat exchangers, microchannel heat exchangers can effectively reduce the amount of refrigerant injection and improve economy, and are widely concerned by enterprises and are being researched and developed. Microchannel heat exchangers have many branches, and the manifolds and microchannel flat tubes have resistance. When the heat exchanger is used as an evaporator, the liquid distributor tube has the problem of uneven flow distribution when distributing the microchannel flat tubes, which directly affects the heat exchange efficiency of the heat exchanger, resulting in increased power consumption, reduced economy and comfort, and the refrigerant needs to be evenly distributed to the inlet flat tubes. It is imperative to provide a new diversion structure for microchannel heat exchangers and improve the uniformity of diversion to reduce flow resistance and improve performance.

[0003] The related art discloses an air conditioning heat exchanger, in which the first flow-dividing structure has a ladder-shaped connecting structure, and the refrigerant forms a circulating flow and mixing in this connecting cavity, thereby achieving full mixing and uniform flow-dividing of the inflowing gas-liquid two-phase refrigerant, and the refrigerant can enter the heat exchange tube in a uniform mist form. However, the circulating flow needs to overcome the influence of gravity at the height of the entire heat exchanger, the influence of right-angle turns, and the influence of small-diameter connecting pipes, and the structure is complex, the pressure loss is large, and the overall performance of the system is affected.

[0004] The related art discloses a flow uniform distribution device, including a flow splitting mechanism, a flow splitting mechanism, a buffer chamber and an inlet pipe are connected in sequence, an ascending pipe, a descending branch pipe, a first flow splitting chamber and a second flow splitting chamber are arranged in sequence from the inside to the outside, and a plurality of descending branches are distributed along the circumference of the ascending pipe, so as to solve the flow splitting problem in the case of multiple branches of a double-row microchannel heat exchanger. However, the distribution structure is complex and not easy to mass produce. The refrigerant repeatedly reverses the flow up and down, resulting in serious energy loss and large pressure loss, which affects the overall performance of the system. Summary of the invention

[0005] The present invention provides a fluid flow splitting structure, a heat exchanger, an outdoor unit and an air conditioner, which can solve the technical problem that the refrigerant in the header is unevenly distributed to each microchannel flat tube due to overcoming gravity and flow resistance during flow splitting.

[0006] The present invention provides a fluid flow distribution structure, which includes a first collecting pipe and a first flow guiding pipe;

[0007] The first current collector is annular, and along the circumference of the first current collector, the inner cavity of the first current collector forms a first annular flow channel, and a first end surface of the first current collector is provided with a plurality of first connecting holes, and the first connecting holes are used to connect with the flat tubes;

[0008] The first flow guide pipe includes a flow guide pipe body and a bent pipe that are connected to 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 bent pipe are connected to each other, the flow guide pipe body and the inner cavity of the bent pipe form a bent flow guide channel, the second end of the bent pipe is connected to the first collecting pipe or is arranged in the first collecting pipe, and the bent flow guide channel is connected to the first annular flow channel.

[0009] In some embodiments, the bent pipe is L-shaped, and in the axial direction of the flow guide pipe body, the second end of the bent pipe is bent in the first direction, and the second end of the bent pipe is connected to the first collecting pipe.

[0010] In some embodiments, the bent pipe includes a first pipe segment and a second pipe segment that are interconnected, wherein one end of the first pipe segment away from the second pipe segment is connected to the flow guide pipe body, and the second pipe segment is a tapered structure, wherein one end of the second pipe segment away from the first pipe segment extends into the first collecting pipe.

[0011] In some embodiments, the elbow is a bifurcated structure, and the elbow is disposed in the first header.

[0012] In some embodiments, the bent pipe includes a first branch pipe segment and a second branch pipe segment, one end of the first branch pipe segment and the second branch pipe segment are both connected to the flow guide pipe body, and in the axial direction of the flow guide pipe body, the other end of the first branch pipe segment is bent in the first direction, and the other end of the second branch pipe segment is bent in the 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 includes a collecting pipe body and a connecting pipe body, the collecting pipe body has a first end head and a second end head far away from each other, the first end head and the second end head are closed, the first end head is provided with a first connecting hole, the second end head is provided with a second connecting hole, the two ends of the connecting pipe body are respectively connected to the first connecting hole and the second connecting hole, and the inner cavity of the connecting pipe body forms a connecting flow channel, the connecting flow channel is connected to the first annular flow channel, and the second end of the bent pipe is connected to the first end head.

[0014] In some embodiments, it also includes a second collecting pipe and a second flow guide pipe, the second collecting pipe is annular, and the inner cavity of the second collecting pipe forms a second annular flow channel along the circumference of the second collecting pipe, and a plurality of second connecting holes are arranged on the first end face of the second collecting pipe, and the second connecting holes are used to connect with the flat tube, and the first collecting pipe and the second collecting pipe are respectively arranged at the two ends of the flat tube; the first end of the second flow guide pipe extends out of the second collecting pipe, and the second end of the second flow guide pipe is connected to the second collecting pipe.

[0015] In some embodiments, the second end of the second flow guide tube is closed and extends into the second collecting pipe. The inner cavity of the second flow guide tube has a straight flow channel. The outer wall of the second end of the second flow guide tube is provided with a flow hole. The straight flow channel is connected with the second annular flow channel through the flow hole.

[0016] In some embodiments, the outer wall of the second end of the second flow guide pipe is provided with at least two flow guide holes, and the first flow guide hole and the second flow guide hole are arranged opposite to each other to form a first branch flow channel and a second branch flow channel between the straight flow channel and the second annular flow channel.

[0017] In some embodiments, along the circumference of the second collecting tube, the first end face of the second collecting tube has a first area and a second area, a plurality of the second connecting holes are arranged in the first area, and the second area is a hole-free area; the outer peripheral wall of the second collecting tube is provided with a guide connecting hole, the second end of the second guiding tube extends into the second collecting tube through the guide connecting hole, and the guide flow hole is arranged corresponding to the second area.

[0018] A heat exchanger includes a fluid diversion structure and a plurality of microchannel flat tubes and fins. The fluid diversion structure is the above-mentioned fluid diversion structure, the plurality of microchannel flat tubes are arranged at intervals along the circumferential direction of the first collecting pipe, and the plurality of fins are arranged at intervals along the axial direction of the microchannel flat tubes.

[0019] In some embodiments, the fin is annular, and the inner diameter and outer diameter of the fin are smaller than the inner diameter and outer diameter of the first collecting tube. Along the circumferential direction of the fin, a plurality of slots are provided on the fin, and the slots are connected to the microchannel heat exchange flat tubes.

[0020] An outdoor unit comprises a heat exchanger, wherein the heat exchanger is the above-mentioned heat exchanger.

[0021] An air conditioner comprises an outdoor unit, wherein the outdoor unit is the outdoor unit described above.

[0022] The present invention provides a fluid flow splitting structure, a heat exchanger, an outdoor unit and an air conditioner, which have the following beneficial effects:

[0023] The present invention improves the vertical unidirectional manifold in the traditional microchannel heat exchanger into a single annular closed manifold (first manifold). When the total number of microchannel flat tube flow paths remains unchanged, the overall spatial height of the annular first manifold will be about 2 times less than that of the vertical unidirectional manifold, that is, the vertical direction will overcome about 2 times less gravity. The annular first manifold can make the refrigerant evenly distributed in the heat exchanger, improve the heat exchange efficiency, and due to the design of the annular manifold, 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 a suitable refrigerant flow rate, thereby achieving uniform heat exchange, so that the design of the annular first manifold can adapt to both cooling and heating modes, whether as a condenser or an evaporator, it can ensure the uniform distribution and flow of the refrigerant, and improve the adaptability and reliability of the heat exchanger. The coordinated use of the first collecting pipe and the first guide pipe can evenly distribute the refrigerant in the heat exchanger and improve the heat exchange efficiency. The refrigerant can evenly enter each flat tube through the annular flow channel of the first collecting pipe and the bent guide channel of the first guide pipe, thereby improving the heat exchange efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the implementation methods of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for the implementation methods or the description of the prior art. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0025] Figure 1 is a schematic diagram of a heat exchanger according to an embodiment of the present invention;

[0026] Figure 2 is an isometric schematic diagram of a first current collecting tube according to an embodiment of the present invention;

[0027] Figure 3 is another isometric schematic diagram of the first header according to an embodiment of the present invention;

[0028] Figure 4 is a schematic diagram of a first flow guide tube according to an embodiment of the present invention;

[0029] Figure 5 A schematic diagram of the connection between the first flow guide pipe and the first current collecting pipe according to an embodiment of the present invention;

[0030] Figure 6 is an isometric schematic diagram of a second current collecting tube according to an embodiment of the present invention;

[0031] Figure 7 is another isometric schematic diagram of the second header according to an embodiment of the present invention;

[0032] Figure 8 is an isometric schematic diagram of a second flow guide tube according to an embodiment of the present invention;

[0033] Fig. 9 is another isometric schematic diagram of the second flow guide tube according to an embodiment of the present invention;

[0034] Fig.10 is another isometric schematic diagram of the second flow guide tube according to an embodiment of the present invention;

[0035] Fig.11 A schematic diagram of the connection between the second flow guide pipe and the second current collecting pipe according to an embodiment of the present invention;

[0036] Fig.12 is an isometric schematic diagram of a second implementation mode of the first flow guide tube according to an embodiment of the present invention;

[0037] Fig.13 Another isometric schematic diagram of a second implementation mode of the first flow guide tube according to an embodiment of the present invention;

[0038] Fig.14 A schematic diagram of a second implementation of the first flow guide pipe according to an embodiment of the present invention being connected to a first current collecting pipe;

[0039] Fig.15 is a schematic diagram of a second embodiment of a heat exchanger according to an embodiment of the present invention;

[0040] Fig.16 is a schematic diagram of a fin according to an embodiment of the present invention;

[0041] Fig.17 is another schematic diagram of a fin according to an embodiment of the present invention;

[0042] Fig.18 Schematic diagram of the angle α according to an embodiment of the present invention.

[0043] Figures: 1-first manifold; 11-first annular flow channel; 12-first end face of first manifold; 101-manifold body; 111-first end head; 112-second end head; 113-first connecting hole; 114-second connecting hole; 115-installation through hole; 102-connecting tube body; 121-connecting flow channel; 103-first connecting hole; 2-first flow guide tube; 3-flow guide tube body; 31-first end of flow guide tube body; 32-second end of flow guide tube body; 4-elbow; 41-first end of elbow; 42-second end of elbow; 43-bending 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 collecting pipe; 51-second annular flow channel; 52-first area; 53-second area; 501-second connecting hole; 502-flow guiding connecting hole; 6-second flow guiding pipe; 61-first end of second flow guiding pipe; 62-second end of second flow guiding pipe; 63-straight flow guiding channel; 601-flow guiding hole; 7-microchannel flat tube; 8-fin; 801-slot; 9-spoiler. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0046] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0047] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0048] See also Figures 1 to 5 As shown, according to an embodiment of the present invention, a fluid diversion structure is provided, which includes a first header 1 and a first flow guide pipe 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, and a first end surface 12 of the first header 1 is provided with a plurality of first connecting holes 103, and the first connecting holes 103 are used to connect with the flat tube; the first flow guide pipe 2 includes a flow guide pipe body 3 and a bent pipe 4 that are connected to each other, the first end 31 of the flow guide pipe body 3 extends out of the first header 1, the second end 32 of the flow guide pipe body 3 and the first end 41 of the bent pipe 4 are connected to each other, the inner cavity of the flow guide pipe body 3 and the bent pipe 4 forms a bent flow guide channel 43, the second end 42 of the bent pipe 4 is connected to the first header 1 or is arranged in the first header 1, and the bent flow guide channel 43 is connected to the first annular flow channel 11.

[0049] Specifically, the refrigerant flows into the guide pipe body 3 from the first end 31 of the guide pipe body 3, and then flows into the bent pipe 4 from the first end 41 of the bent pipe 4, that is, the refrigerant flows in the bent guide channel 43. When the refrigerant flows out from the second end 42 of the bent pipe 4, it flows into the first collecting pipe 1. Since the inner cavity of the first collecting pipe 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 diversion structure is applied to the heat exchanger, during cooling, 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. The refrigerant then flows through the guide tube body 3 and the elbow 4 in sequence, and then enters the next process; during heating, the heat exchanger as a whole acts as an evaporator, and the flow direction of the entire refrigerant is opposite to the flow direction when the heat exchanger acts as a condenser. The throttled gas-liquid two-phase refrigerant flows from the first end 31 of the guide tube body 3 into the guide tube body 3, and then flows into the elbow 4, that is, the gas-liquid two-phase refrigerant flows in the bent guide channel 43, and then flows into the first header 1 from the second end 42 of the elbow 4, and circulates in the first annular flow channel 11. In this process, the gas-liquid two-phase refrigerant will enter the flat tube, and the refrigerant will evaporate and exchange heat in the microchannel flat tube 7. After completing the evaporation and heat exchange, the refrigerant vapor flows out of the flat tube and enters the next process.

[0051] In this embodiment, the vertical unidirectional manifold in the traditional microchannel heat exchanger is improved into a single annular closed manifold (first manifold 1). When the total number of microchannel flat tubes 7 flow paths remains unchanged, the overall spatial height of the annular first manifold 1 will be about 2 times less than that of the vertical unidirectional manifold, that is, the vertical direction will overcome about 2 times less gravity. The annular first manifold 1 can make the refrigerant evenly distributed in the heat exchanger, improve the heat exchange efficiency, and due to the design of the annular manifold, the refrigerant can flow evenly in the first annular flow channel 11 and be distributed to each flat tube, ensuring that each heat exchange unit can obtain a suitable refrigerant flow, thereby achieving uniform heat exchange, so that the design of the annular first manifold 1 can adapt to both cooling and heating modes, whether as a condenser or an evaporator, it can ensure the uniform distribution and flow of the refrigerant, and improve the adaptability and reliability of the heat exchanger. The coordinated use of the first collecting pipe 1 and the first guide pipe 2 can evenly distribute the refrigerant in the heat exchanger, thereby improving the heat exchange efficiency. Through the annular flow channel of the first collecting pipe 1 and the bent guide channel 43 of the first guide pipe 2, the refrigerant can evenly enter each flat tube, thereby improving the heat exchange efficiency.

[0052] In addition, the first flow guide 2 includes an elbow 4. The function of the elbow 4 is to change the flow direction of the fluid, so that the fluid can flow in from the flow guide body 3, change direction after passing through the elbow 4, and then flow into the first header 1. The change in flow direction helps to evenly distribute and mix the fluid in the heat exchanger, thereby improving the heat exchange efficiency. The setting of the elbow 4 can reduce the resistance in the flow process of the fluid. Compared with a right-angle turn, the elbow 4 can more smoothly guide the fluid to change direction, reducing the energy loss and pressure loss caused by the right-angle turn. Then, the first flow guide 2 is installed at the refrigerant inlet of the first header 1, that is, the speed direction of the refrigerant is set at an angle with the first header 1 here, reducing the reflection effect of the refrigerant directly impacting the wall, so that the refrigerant circulates in the annular first header 1, and the refrigerant circulates in the annular header by using the initial velocity of the refrigerant itself to overcome less gravity, thereby reducing the pressure drop, completing uniform diversion, and enhancing the performance of the heat exchanger. Moreover, through the setting of the bent pipe 4, the refrigerant can flow in the bent guide channel 43 before entering the annular collecting pipe, which is conducive to the mixing of the gas-liquid two-phase refrigerant, so that the refrigerant enters the heat exchange tube in a more uniform mist form, thereby improving the heat exchange efficiency. In the design of the air-conditioning heat exchanger, the bent pipe 4 can adapt to different spatial layout requirements, so that the pipeline can 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 combination with Fig.18 As shown, the first manifold 1 is provided with a mounting through hole 115 for mounting the first flow guide pipe 2, and an angle α is formed between the central axis of the pipe opening of the elbow 4 and the central axis of the mounting through hole 115, and the range of the angle α is 10° to 30°. In this embodiment, the angle α is formed between the velocity direction of the refrigerant and the inner wall of the first manifold 1 by providing the elbow 4. In other embodiments, the angle α can also be achieved by changing the opening angle of the refrigerant inlet of the first manifold 1, and the angle is formed between the elbow 4 and the inner wall of the first manifold 1.

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

[0055] Specifically, the refrigerant first flows in from the first end 31 of the flow guide tube body 3. At this time, the refrigerant flows along the axial direction of the flow guide tube body 3. When the refrigerant reaches the second end 32 of the flow guide tube body 3, due to the L-shaped design of the elbow 4, the flow direction of the refrigerant changes, so that the refrigerant bends along the first direction at the second end 42 of the elbow 4, thereby adjusting the flow direction. The refrigerant then flows into the elbow 4 and continues to flow along the bent flow guide 43 of the elbow 4. After the refrigerant flows out from 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 a first annular flow channel 11, the refrigerant flows in the first annular flow channel 11 and is distributed to each flat tube. In the cooling mode, the refrigerant exchanges heat in the flat tubes and then flows into the first header 1, flows through the flow guide tube body 3 and the elbow 4 in sequence, and then enters the next 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 guide channel 43, and then flows into the first collecting pipe 1 from the second end 42 of the bent pipe 4, and circulates in the first annular flow channel 11. During this process, the gas-liquid two-phase refrigerant will enter the flat tube to complete evaporation heat exchange.

[0056] In this embodiment, the L-shaped bend 4 helps to reduce the pressure drop during the flow of the refrigerant. By changing the flow direction, the L-shaped bend 4 can reduce the reflection effect of the refrigerant directly impacting the wall surface, and help the refrigerant to circulate in the annular first collecting pipe 1. The initial velocity of the refrigerant itself is used to overcome less gravity, thereby reducing the pressure drop and completing uniform diversion.

[0057] It is worth noting that, based on the orientation shown in the figure, the first direction is rightward relative to the axial direction of the flow guide tube body 3, and 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 diversion of the refrigerant, the second end 42 of the elbow 4 is set in the opposite direction. The turning angle of the elbow ranges from 70° to 90°, and a reasonable turning angle can also be given according to actual conditions.

[0058] See also Figures 1 to 5 As shown, the elbow 4 includes a first pipe section 401 and a second pipe section 402 that are connected to each other. The end of the first pipe section 401 away from the second pipe section 402 is connected to the flow guide pipe body 3, and the second pipe section 402 is a constricted structure. The end of the second pipe section 402 away from the first pipe section 401 extends into the first collecting pipe 1.

[0059] In this embodiment, the specific bending of the elbow 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 during the flow of the fluid, especially when the fluid passes through the elbow 4, the necking can increase the fluid flow rate, thereby reducing the pressure drop. At the necking, the fluid flow rate increases. According to the continuity equation and the Bernoulli equation, the increase in flow rate will lead to a decrease in local pressure, and this pressure reduction is helpful for throttling and reducing the pressure of the refrigerant. In addition, the necking structure can reduce the situation where the fluid directly impacts the wall of the elbow 4, reducing the reflection and vibration caused thereby. In other embodiments, the necking structure can adapt to different flow requirements by changing its size, providing a certain flow regulation capability for the system.

[0060] As a specific implementation, the diameter of the second pipe section 402 as a shrinking structure is between 1 / 2 and 3 / 4 of the diameter of the flow guide pipe body 3, and a reasonable shrinking diameter can also be given according to actual conditions.

[0061] See also Figures 1 to 5 As shown, the first collecting pipe 1 includes 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 far 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 connecting hole 113, the second end head 112 is provided with a second connecting hole 114, the two ends of the connecting pipe body 102 are respectively connected to the first connecting hole 113 and the connecting hole, and the inner cavity of the connecting pipe body 102 forms a connecting flow channel 121, the connecting flow channel 121 is connected to the first annular flow channel 11, and the second end 42 of the elbow 4 is connected to the first end head 111.

[0062] Specifically, the connecting pipe body 102 is arc-shaped, and the first guide pipe 2 is L-shaped. The refrigerant first flows in from the first end 31 of the guide pipe body 3. At this time, the refrigerant flows along the axial direction of the guide pipe body 3. When the refrigerant reaches the second end 32 of the guide pipe body 3, due to the L-shaped design of the bend 4, the flow direction of the refrigerant changes, so that the refrigerant is bent along the first direction at the second end 42 of the bend 4, thereby adjusting the flow direction. The refrigerant then flows into the bend 4 and continues to flow along the bent guide channel 43 of the bend 4. After the refrigerant flows out from 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 a first annular flow channel 11, the refrigerant flows in the first annular flow channel 11 and is distributed to each flat tube. Some of the refrigerant that is not diverted to the flat tube continues to flow into the connecting tube body 102, flows in the connecting flow channel 121, flows out of the connecting flow channel 121, and then flows into the header body 101, mixes with the refrigerant flowing out of the elbow 4, and is diverted again. In the cooling mode, the refrigerant exchanges heat in the flat tubes and then flows into the first header 1, flows through the guide tube body 3 and the elbow 4 in sequence, and then enters the next 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 guide channel 43, and then flows into the first collecting pipe 1 from the second end 42 of the bent pipe 4, and circulates in the first annular flow channel 11. During this process, the gas-liquid two-phase refrigerant will enter the flat tube to complete evaporation heat exchange, and the undivided refrigerant will flow into the connecting pipe body 102, and then flow into the first collecting pipe 1 for circulation.

[0063] In this embodiment, the refrigerant flows counterclockwise in the first manifold 1, the elbow 4 bends to the right, and the refrigerant also flows counterclockwise in the connecting tube body 102. Through the design of the first manifold 1 and the connecting tube body 102, the refrigerant can be more evenly distributed to each flat tube, improving the heat exchange efficiency. The refrigerant that is not diverted to the flat tube flows into the connecting tube body 102, and then flows into the manifold body 101 again to mix with the refrigerant flowing out of the elbow 4, realizing the circulation of the refrigerant, which helps to further evenly distribute and improve the heat exchange efficiency, and reduces the dead zone and short circuit in the refrigerant flow, reduces energy loss, and improves the overall performance of the system. The design of the connecting tube 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 sets the circulating flow mode after the connecting tube body 102. The circulating flow reduces the dead corners and retention 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 noting that in this embodiment, when the first manifold 1 includes a manifold body 101 and a connecting tube body 102, the first flow guide tube 2 is preferably L-shaped. This is because the refrigerant flows counterclockwise in the first manifold 1 to form a circulating flow.

[0065] As a specific implementation, a spoiler 9 is provided on the flow guide tube body 3. The spoiler 9 changes the flow direction of the fluid and increases the instability of the fluid flow, thereby generating an unstable flow state such as turbulence or eddy current, 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 tube, strengthen the heat exchange, and greatly improve the heat exchange coefficient. The spoiler 9 can play a role in both laminar flow and turbulent flow, and achieve the purpose of mixed turbulence through different flow characteristics.

[0066] As a specific embodiment, the first end 111 is provided with an installation hole 115 for installing the first flow guide pipe 2, and the first connecting hole 113 is located radially inside the installation hole 115. This arrangement facilitates the refrigerant in the first flow guide pipe 2 to flow out of the first flow guide pipe 2 and will not affect the flow of the refrigerant in the connecting pipe body 102.

[0067] See also Figures 1 to 11 As shown, it also includes a second collecting pipe 5 and a second flow guiding pipe 6. The second collecting pipe 5 is annular. Along the circumference of the second collecting pipe 5, the inner cavity of the second collecting pipe 5 forms a second annular flow channel 51. A first end face of the second collecting pipe 5 is provided with a plurality of second connecting holes 501. The second connecting holes 501 are used to connect with the flat tube. The first collecting pipe 1 and the second collecting pipe 5 are respectively provided at the two ends of the flat tube; the first end 61 of the second flow guiding pipe 6 extends out of the second collecting pipe 5, and the second end 62 of the second flow guiding pipe 6 is connected to the second collecting pipe 5.

[0068] Specifically, during refrigeration, the heat exchanger acts as a condenser, and the high-temperature and high-pressure refrigerant vapor from the compressor exhaust port flows from the second guide pipe 6 into the second header 5, and is divided in the second header 5, and the refrigerant vapor enters all the microchannel flat tubes 7. At this time, the refrigerant vapor in the microchannel flat tubes 7 has begun to exchange heat with the outside and condense. When the refrigerant liquid in all the microchannel flat tubes 7 has completed condensation, it enters the first header 1, gathers together, and then flows through the first guide pipe 2 and the spoiler 9 in sequence, and enters the next process after coming out of the spoiler 9.

[0069] Specifically, when heating, the 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 enters the turbulence chamber from the inlet of the turbulent 9, and the gas and liquid of the refrigerant are evenly mixed after the turbulence. The refrigerant flows into the first guide pipe 2 and then into the first header 1, and circulates therein. In this process, the gas-liquid two-phase refrigerant enters the microchannel flat tube 7, and the refrigerant evaporates and exchanges heat in the microchannel flat tube 7. After the evaporation and heat exchange, the refrigerant vapor gathers in the second header 5, and finally enters the next process through the second guide pipe 6.

[0070] In this embodiment, through the coordinated use of the header and the guide tube, the refrigerant can be more evenly distributed to each microchannel flat tube 7, thereby improving the heat exchange efficiency. In the cooling mode, the heat exchanger acts as a condenser, and the high-temperature and high-pressure refrigerant vapor is diverted in the second header 5 and enters the microchannel flat tube 7 for condensation; 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 enables the heat exchanger to adapt to different working modes. The first header 1 and the second header 5 are both arranged in an annular shape, and the annular header helps to achieve uniform distribution of the fluid in the heat exchanger. This design can ensure that the refrigerant is evenly diverted before entering the microchannel flat tube 7, thereby improving the heat exchange efficiency, and in the cooling and heating modes, the annular header can adapt to the change in the flow direction when the heat exchanger acts as a condenser and an evaporator, thereby ensuring uniform distribution and flow of the refrigerant.

[0071] As a specific implementation method, the cross-sectional shape of the first collecting tube 1 and the second collecting tube 5 is irregular, specifically, the cross-sectional shape includes a rectangular segment and a circular arc segment, and the end surface of the first collecting tube 1 and the second collecting tube 5 for installing the flat tube is a plane. This plane setting of the present embodiment allows the flat tube to be inserted without a long distance and to utilize a limited area for heat exchange. In conventional circular-section collecting tubes, in order to install the flat tubes, the flat tubes are usually installed in the collecting tubes with a long length.

[0072] See also Figures 1 to 11 As shown, the second end 62 of the second flow guide tube 6 is closed and extends into the second collecting pipe 5. The inner cavity of the second flow guide tube 6 has a straight flow channel 63. The outer wall of the second end 62 of the second flow guide tube 6 is provided with a flow guide hole 601. The straight flow channel 63 is connected to the second annular flow channel 51 through the flow guide hole 601. The flow guide hole 601 is used to discharge refrigerant vapor and absorb refrigerant vapor.

[0073] Specifically, during refrigeration, the refrigerant first flows into the second flow guide pipe 6 in the state of high-temperature and high-pressure steam from the exhaust port of the compressor, and then flows into the second header 5 through the straight-through flow guide channel 63 of the second flow guide pipe 6, and is divided in the second header 5. Since the second end 62 of the second flow guide pipe 6 extends into the second header 5, and the outer wall of the second end is provided with a flow guide hole 601, the refrigerant flows into the second annular flow channel 51 from the straight-through flow guide channel 63 through these flow guide holes 601, and the divided refrigerant vapor enters all the microchannel flat tubes 7, starts to exchange heat with the outside, and condenses; when the refrigerant liquid in all the microchannel flat tubes 7 is condensed, it enters the first header 1 and converges together. The refrigerant liquid gathered in the first header 1 then flows through the first flow guide pipe 2 and the spoiler 9 in sequence, and enters the next process after coming out of the spoiler 9.

[0074] In this embodiment, although the refrigerant can flow from the first flow conduit 2 or the second flow conduit 6 by reversing, the refrigerant flowing into the second flow conduit 6 is always a gaseous refrigerant, while the refrigerant flowing into the first flow conduit 2 is always a gas-liquid two-phase refrigerant, and the liquid refrigerant accounts for a larger proportion. Therefore, the structures of the first flow conduit 2 and the second flow conduit 6 are different. The guide hole 601 of the second flow conduit 6 is connected to the annular flow channel of the second header 5, which can achieve a more uniform distribution of the refrigerant, reduce the erosion of the fluid medium on the heat exchange tube, and enhance the heat transfer performance. In places where flat tubes are not arranged, the first header 1 is connected using an arc-shaped connecting tube body. The arc-shaped tube connection is used here, firstly, it can save materials, and secondly, a structure of sudden contraction and sudden expansion is formed from the first end 111 to the second end 112, which has the function of drainage. This function helps the diversion of the two-phase flow during heating and completes the circulation.

[0075] See also Figures 1 to 11 As shown, at least two flow holes 601 are disposed on the outer wall of the second end 62 of the second flow guide pipe 6 , and the first flow hole 601 and the second flow hole 601 are disposed opposite to each other to form a first branch flow channel and a second branch flow channel between the straight flow channel 63 and the second annular flow channel 51 .

[0076] In this embodiment, two flow guide holes 601 are respectively provided on each side, and two first flow guide holes 601 and second flow guide holes 601 are provided on the peripheral wall of the second flow guide tube 6 at different angles in the circumferential direction. The refrigerant first flows into the straight flow guide channel 63 of the second flow guide tube 6 from the high-temperature and high-pressure steam state coming out of the compressor exhaust port, and the refrigerant flows into the second header 5 through the straight flow guide channel 63 of the second flow guide tube 6, and is divided in the second header 5. Since at least two flow guide holes 601 are provided on the outer wall of the second end 62 of the second flow guide tube 6, the first and second flow guide holes 601 are arranged oppositely, and the refrigerant flows from the straight flow guide channel 63 into the second annular flow channel 51 through these flow guide holes 601, forming a first flow branch channel and a second flow branch channel, and the divided refrigerant vapor enters all the microchannel flat tubes 7, starts to exchange heat with the outside, and condenses. In this embodiment, two opposite flow guide holes 601 are provided on the outer wall of the second end 62 of the second flow guide tube 6, so that a first branch flow channel and a second branch flow channel can be formed between the straight flow channel 63 and the second annular flow channel 51, thereby achieving more uniform distribution of the refrigerant.

[0077] See also Figures 1 to 11 As shown, along the circumference of the second collecting tube 5, the first end face of the second collecting tube 5 has a first area 52 and a second area 53, a plurality of second connecting holes 501 are arranged in the first area 52, and the second area 53 is a non-porous area; the outer peripheral wall of the second collecting tube 5 is provided with a guide connecting hole 502, the second end 62 of the second guiding tube 6 passes through the guide connecting hole 502 and extends into the second collecting tube 5, the guide flow hole 601 is arranged corresponding to the second area 53, and the distance from the guide connecting hole to the second connecting holes 501 at both ends is equal.

[0078] In this embodiment, taking the cross section of the second collecting tube 5 as the projection surface, the central angle of the second area 53 is greater than 90°. Under the influence of gravity, liquid accumulation is inevitable in this area. No holes are opened in the second area 53 to avoid liquid accumulation here and reduce the poor flow caused by liquid accumulation. In addition, the non-porous area can help concentrate the fluid flow, so that the refrigerant passes through the porous first area 52 more evenly, thereby improving the heat exchange efficiency.

[0079] It is worth noting that no hole is set in the second area 53, and the corresponding area of ​​the corresponding first collecting pipe 1 is actually not set with holes for installing flat tubes. The corresponding first collecting pipe 1 is provided with a connecting tube body 102 at this position. In this way, the first collecting pipe 1 and the second collecting pipe 5 are not provided with corresponding flat tube installation holes.

[0080] See also Figures 1 to 15 As shown, as another embodiment, the elbow 4 is a bifurcated structure, and the elbow 4 is arranged in the first collecting pipe 1.

[0081] Specifically, the refrigerant first flows in from the first end 31 of the guide pipe body 3 and flows along the axial direction of the guide pipe body 3. When the refrigerant reaches the second end 32 of the guide pipe body 3 and the connection between the guide pipe body 3 and the elbow 4, the refrigerant will be diverted into two or more channels due to the bifurcated structure of the elbow 4. The bifurcated refrigerant flow paths will respectively enter different areas of the first collecting pipe 1. After flowing out from the second end 42 of the elbow 4, the refrigerant flows into the first collecting pipe 1. Since the inner cavity of the first collecting 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.

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

[0083] See also Figures 1 to 15 As shown, the bent pipe 4 includes a first branch pipe segment 403 and a second branch pipe segment 404, one end of the first branch pipe segment 403 and the second branch pipe segment 404 are both connected to the guide pipe body 3, in the axial direction of the guide pipe body 3, the other end of the first branch pipe segment 403 is bent in the first direction, and the other end of the second branch pipe segment 404 is bent in the second direction, a first branch flow channel 44 is formed between the first branch pipe segment 403 and the guide pipe body 3, and a second branch flow channel 45 is formed between the second branch pipe segment 404 and the guide pipe body 3.

[0084] Specifically, the refrigerant first flows in from the first end 31 of the flow guide pipe body 3, and flows along the axial direction of the flow guide pipe body 3. After the refrigerant reaches the connection between the flow guide pipe body 3 and the elbow 4, it is diverted to two branch pipe sections. One end of the first branch pipe section 403 and the second branch pipe section 404 are both connected to the flow guide pipe body 3 to form two branch flow channels. The refrigerant flows in the first branch pipe section 403 and the second branch pipe section 404. The other ends of the two branch pipe sections are bent in the first direction and the second direction respectively. The other end of the first branch pipe section 403 extends into the first header 1, and the other end of the second branch pipe section 404 also extends into the first header 1, but in a different direction from the first branch pipe section 403. In this way, the refrigerant enters the first header 1 through the two branch pipe sections, forming two flow channels in opposite directions, and diverting from two directions. When the refrigerant flow pressure is large enough, the refrigerant in the two flow channels will have an impact to achieve refrigerant mixing.

[0085] In this embodiment, the first direction is to the right, and the second direction is to the left. The design of the two branch flow channels can make the refrigerant more evenly distributed in the first manifold 1, reduce the separation of the gas-liquid two-phase, and improve the uniformity of the diversion. By reasonably designing the bending angle, bending radius and pipeline diameter of the branch pipe section, the distributor connecting pipe structure can be optimized to reduce the problem of uneven diversion. The reason why the present embodiment can realize two branch flow channels is that the entire bend 4 is set in the first manifold 1, so that even if the bend 4 is to be bifurcated, the refrigerant flow direction can be changed, and the reflection effect of the refrigerant directly impacting the wall surface can be reduced, so that the refrigerant circulates in the annular first manifold 1. The refrigerant circulates in the annular first manifold 1 by using the initial velocity of the refrigerant itself to overcome less gravity, thereby reducing the pressure drop, completing uniform diversion, and enhancing the performance of the heat exchanger.

[0086] As a specific implementation method, when the elbow 4 is a bifurcated structure, the turning angle of the unidirectional elbow ranges from 70° to 90°, and a reasonable turning angle can also be given according to actual conditions. The pipe mouth of the branch pipe section of the elbow is a constricted structure. In order to enhance the speed of the two-phase mixed flow during heating, the constriction range is related to the flow rate of the refrigerant in the system. Here, the diameter of the constriction is between 1 / 2 and 3 / 4 of the diameter of the flow guide body 3, and a reasonable constriction diameter can also be given according to actual conditions. The first collecting pipe 1 and the second collecting pipe 5 are both complete rings, but in order to avoid dead corners in the collecting pipes, the collecting pipes are still not provided with holes for installing flat tubes at the positions where the corresponding flow guide pipes are installed. Compared with the elbow 4 of the unidirectional elbow, the maximum flow path of the refrigerant diversion in the diversion elbow using a bifurcated structure is halved, which is conducive to reducing the diversion pressure drop and increasing the diversion effect.

[0087] See also Figure 1 and Fig.15 As shown, a heat exchanger includes a fluid diversion structure and a plurality of microchannel flat tubes 7 and fins 8, characterized in that the fluid diversion structure is the above-mentioned fluid diversion structure, the plurality of microchannel flat tubes 7 are arranged at intervals along the circumferential direction of the first collecting pipe 1, and the plurality of fins 8 are arranged at intervals along the axial direction of the microchannel flat tubes 7.

[0088] In this embodiment, the use of microchannel flat tubes 7 and fins 8 can significantly increase the heat exchange area, make the heat transfer between cold and hot fluids more sufficient, thereby improving the heat transfer rate and overall efficiency of the heat exchanger. The shape and arrangement of fins 8 can affect the flow state of the fluid in the tube. Reasonable design can reduce the flow resistance of the fluid, improve the fluid disturbance, promote the formation of turbulence in the fluid, and enhance the heat transfer effect. Since the first header 1 and the second header 5 are annular, the microchannel flat tubes 7 on the entire heat exchanger also present an annular arrangement, which is quite different from the flat heat exchanger. The fins 8 used here are different from the ordinary straight fins 8. The microchannel flat tubes 7 and annular fins 8 structure of this embodiment form many different angles with the horizontal plane in space, which is conducive to drainage during defrosting and condensation, and can enhance the overall performance of the heat exchanger. The inner and outer diameters and circumference of the fins 8 can be appropriately adjusted according to the actual needs of the heat exchanger.

[0089] See also Fig.16 and Fig.17 As shown, the fin 8 is annular, and the inner diameter and outer diameter of the fin 8 are smaller than the inner diameter and outer diameter of the first header 1. Along the circumferential direction of the fin 8, a plurality of slots 801 are provided on the fin 8, and the slots 801 are connected to the microchannel heat exchange flat tubes.

[0090] In this embodiment, the fin 8 unit is in the shape of a ring, and the inner diameter and outer diameter are slightly smaller than the inner and outer diameters of the header, respectively, to protect and install the fin 8. A slot 801 of the microchannel flat tube 7 is provided near the inner diameter, and the microchannel flat tube 7 can cooperate to achieve heat conduction. In addition, an impact hole is provided on the microchannel fin 8 to separate adjacent fins 8 to form a gap. The introduction of the impact hole plays a role in turbulence and heat exchange enhancement to a certain extent. The fin 8 is annular and has a plurality of slots 801. When connected with the microchannel heat exchange flat tube, the heat exchange area can be increased, thereby improving the heat exchange efficiency. The inner diameter and outer diameter of the annular fin 8 are both smaller than the inner diameter and outer diameter of the first header 1. This design provides good structural support and enhances the overall stability. The inner diameter and outer diameter of the annular fin 8 are both smaller than the inner diameter and outer diameter of the first header 1. This design provides good structural support and enhances the overall stability. After the fin 8 structure is combined with the structure of the collecting pipe, the heat of the high-temperature fluid in the microchannel flat tube 7 can be transferred to the fin 8 unit by heat conduction (when used as a condenser during cooling), and the fin 8 then takes away the heat by heat convection with the air, thereby achieving the purpose of cooling the high-temperature fluid in the microchannel flat tube 7.

[0091] As a specific implementation, the slot 801 can be opened upward or downward, so that the fin 8 can be inserted from the outer circumference of the flat tube or from the inner circumference of the flat tube.

[0092] An outdoor unit comprises a heat exchanger, the heat exchanger being the heat exchanger mentioned above.

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

[0094] It is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

[0095] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the present invention. The above are only preferred embodiments of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and variations can be made without departing from the technical principles of the present invention, and these improvements and variations should also be regarded as the protection scope of the present invention.

Claims

1. A fluid diversion structure, characterized in that: include: A first collecting pipe (1) and a first flow guiding pipe (2); The first collecting pipe (1) is annular, and along the circumference of the first collecting pipe (1), the inner cavity of the first collecting pipe (1) forms a first annular flow channel (11), and a first end surface (12) of the first collecting pipe (1) is provided with a plurality of first connecting holes (103), and the first connecting holes (103) are used for connecting with the flat tubes; The first flow guide pipe (2) comprises a flow guide pipe body (3) and a curved pipe (4) which are connected to each other; the first end (31) of the flow guide pipe body (3) extends out of the first collecting pipe (1); the second end (32) of the flow guide pipe body (3) and the first end (41) of the curved pipe (4) are connected to each other; the inner cavities of the flow guide pipe body (3) and the curved pipe (4) form a bent flow guide channel (43); the second end (42) of the curved pipe (4) is connected to the first collecting pipe (1) or arranged in the first collecting pipe (1); and the bent flow guide channel (43) is connected to the first annular flow channel (11).

2. The fluid flow distribution structure according to claim 1, characterized in that: The curved pipe (4) is L-shaped, and in the axial direction of the flow guide pipe body (3), the second end (42) of the curved pipe (4) is bent in a first direction, and the second end (42) of the curved pipe (4) is connected to the first collecting pipe (1).

3. The fluid flow distribution structure according to claim 2, characterized in that: The curved pipe (4) comprises a first pipe section (401) and a second pipe section (402) which are connected to each other; an end of the first pipe section (401) away from the second pipe section (402) is connected to the flow guide pipe body (3); the second pipe section (402) is a constricted structure; an end of the second pipe section (402) away from the first pipe section (401) extends into the first collecting pipe (1).

4. The fluid flow distribution structure according to claim 1, characterized in that: The curved pipe (4) is a bifurcated structure, and the curved pipe (4) is arranged in the first collecting pipe (1).

5. The fluid flow distribution structure according to claim 4, characterized in that: The curved 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 one end of the second branch pipe section (404) are both connected to 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; a first branch flow channel (44) is formed between the first branch pipe section (403) and the flow guide pipe body (3), and a second branch flow channel (45) is formed between the second branch pipe section (404) and the flow guide pipe body (3).

6. The fluid flow distribution structure according to claim 1, characterized in that: 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 far away from each other; the first end head (111) and the second end head (112) are arranged in a closed manner; the first end head (111) is provided with a first connecting hole (113); the second end head (112) is provided with a second connecting hole (114); the two ends of the connecting pipe body (102) are respectively connected to the first connecting hole (113) and the second connecting hole (114); the inner cavity of the connecting pipe body (102) forms a connecting flow channel (121); the connecting flow channel (121) is connected to the first annular flow channel (11); the second end (42) of the bent pipe (4) is connected to the first end head (111).

7. The fluid flow distribution structure according to any one of claims 1 to 6, characterized in that: The invention also comprises a second collecting pipe (5) and a second flow guiding pipe (6); the second collecting pipe (5) is annular; along the circumference of the second collecting pipe (5), the inner cavity of the second collecting pipe (5) forms a second annular flow channel (51); a plurality of second connecting holes (501) are arranged on the first end surface of the second collecting pipe (5); the second connecting holes (501) are used for connecting with the flat tube; the first collecting pipe (1) and the second collecting pipe (5) are arranged at the two ends of the flat tube respectively; the first end (61) of the second flow guiding pipe (6) extends out of the second collecting pipe (5), and the second end (62) of the second flow guiding pipe (6) is connected to the second collecting pipe (5).

8. The fluid flow distribution structure according to claim 7, characterized in that: The second end (62) of the second flow guide tube (6) is arranged in a closed manner, and the second end (62) of the second flow guide tube (6) extends into the second collecting pipe (5). The inner cavity of the second flow guide tube (6) has a straight flow channel (63), and the outer wall of the second end (62) of the second flow guide tube (6) is provided with a flow guide hole (601), and the straight flow channel (63) is connected to the second annular flow channel (51) through the flow guide hole (601).

9. The fluid flow distribution structure according to claim 8, characterized in that: The outer wall of the second end (62) of the second flow guide tube (6) is provided with at least two flow guide holes (601), and the first flow guide hole (601) and the second flow guide hole (601) are arranged opposite to each other, so that a first branch flow channel and a second branch flow channel are formed between the straight flow guide channel (63) and the second annular flow channel (51).

10. The fluid flow distribution structure according to claim 8, characterized in that: Along the circumference of the second collecting tube (5), the first end surface of the second collecting tube (5) has a first area (52) and a second area (53), a plurality of the second connecting holes (501) are arranged in the first area (52), and the second area (53) is a non-hole area; the outer peripheral wall of the second collecting tube (5) is provided with a flow guiding connecting hole (502), the second end (62) of the second flow guiding tube (6) passes through the flow guiding connecting hole (502) and extends into the second collecting tube (5), and the flow guiding hole (601) is arranged corresponding to the second area (53).

11. A heat exchanger comprising a fluid flow splitting structure and a plurality of microchannel flat tubes (7) and fins (8), characterized in that: The fluid diversion structure is the fluid diversion structure described in any one of claims 1 to 10, wherein the plurality of microchannel flat tubes (7) are arranged at intervals along the circumferential direction of the first collecting pipe (1), and the plurality of fins (8) are arranged at intervals along the axial direction of the microchannel flat tubes (7).

12. The heat exchanger according to claim 1, characterized in that 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 along the circumferential direction of the fin (8), a plurality of slots (801) are provided on the fin (8), and the slots (801) are connected to the microchannel heat exchange flat tubes (7).

13. An outdoor unit, comprising a heat exchanger, characterized in that: The heat exchanger is the heat exchanger according to claim 11 or claim 12.

14. An air conditioner, comprising an outdoor unit, characterized in that: The outdoor unit is the outdoor unit according to claim 13.

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