Microchannel heat exchanger and air conditioning equipment having the same

Abstract

The present invention provides a microchannel heat exchanger and an air conditioning device having the same. The microchannel heat exchanger includes a manifold, the manifold includes a cavity unit with a connecting cavity and a group of first shunt pipes connected to the connecting cavity, the manifold is placed vertically, the cavity unit includes: an injection baffle and a refrigerant injection port, the injection baffle is arranged in the connecting cavity, the refrigerant injection port is located above the injection baffle, and a group of first shunt pipes are all connected to the cavity of the connecting cavity located below the injection baffle; wherein, a plurality of injection holes arranged at intervals are arranged on the injection baffle, so that the refrigerant reaching the top of the injection baffle from the refrigerant injection port is sprayed downward through the injection holes. The microchannel heat exchanger of the present invention solves the problem of uneven flow distribution in the microchannel heat exchanger in the air conditioner of the upper air outlet type in the prior art.

Description

Technical Field

[0001] The present invention relates to the field of heat exchangers, and in particular to a microchannel heat exchanger and air conditioning equipment having the same. Background Art

[0002] In the prior art, microchannel heat exchangers have higher heat exchange efficiency than finned copper tube heat exchangers. They are highly efficient and compact, require less refrigerant, are light in weight and low in cost. They were first used in automotive air conditioners, and later gradually matured and were applied to products such as single-cooling light commercial air conditioners, household air conditioners and water heaters. However, when they were applied to heat pump air conditioners, there was a problem of uneven flow distribution.

[0003] Uneven diversion includes uneven up and down diversion and uneven left and right diversion. Each flat tube of the microchannel heat exchanger has multiple holes distributed laterally. The refrigerant entering the manifold cannot enter the flat tube evenly through the holes, so there is uneven left and right diversion. The manifold of the existing microchannel heat exchanger is usually placed vertically. When this microchannel heat exchanger is installed in the outdoor unit of the air conditioner and used as an evaporator during the heating cycle, the refrigerant in the gas-liquid two-phase state will be affected by gravity and a certain degree of gas-liquid stratification will occur. The gaseous refrigerant is easy to gather in the upper space of the manifold, and the liquid refrigerant is easy to accumulate in the lower space of the manifold. This will make the amount of refrigerant entering each flat tube from the inside of the manifold uneven, resulting in differences in the refrigerant flow rate entering each flat tube arranged from top to bottom, seriously affecting the heat exchange effect.

[0004] In the air conditioner with top air outlet, the difference between the upper and lower wind speeds is large, the wind speed of the flow path located at the top is larger, and the wind speed of the flow path located at the bottom is smaller. Due to the uneven flow distribution of the microchannel heat exchanger, it is also more sensitive to the wind speed difference. The wind speed of the flow path located above the manifold is larger, and the structure located above the manifold in the microchannel heat exchanger can handle more refrigerant, and the number of flat tubes required is also smaller. However, due to the uneven flow distribution of the microchannel heat exchanger, the amount of refrigerant located above the manifold is small, and the microchannel heat exchanger cannot play its role well.

[0005] In addition, compared with the fin copper tube heat exchanger in the prior art, the internal volume of the microchannel heat exchanger is relatively small. When the outdoor unit of the air conditioner adopts a microchannel heat exchanger and the indoor unit adopts a fin copper tube heat exchanger, the air conditioner will have the problem that the optimal refrigerant amount in the heating cycle process is greater than the optimal refrigerant amount in the refrigeration cycle process. Summary of the invention

[0006] The main purpose of the present invention is to provide a microchannel heat exchanger and an air-conditioning device having the same, so as to solve the problem of uneven flow distribution in the microchannel heat exchanger in the top-outlet air-conditioning device in the prior art.

[0007] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, there is provided a microchannel heat exchanger, comprising a manifold, the manifold comprising a cavity unit having a connecting cavity and a group of first branch pipes connected to the connecting cavity, the manifold is placed vertically, the cavity unit comprises: an injection baffle and a refrigerant injection port, the injection baffle is arranged in the connecting cavity, the refrigerant injection port is located above the injection baffle, and a group of first branch pipes are all connected to the cavity of the connecting cavity located below the injection baffle; wherein, a plurality of injection holes arranged at intervals are arranged on the injection baffle, so that the refrigerant reaching the top of the injection baffle from the refrigerant injection port is sprayed downward through the injection holes.

[0008] Furthermore, there are multiple cavity units, and the multiple cavity units are arranged in sequence from top to bottom.

[0009] Furthermore, along the direction from top to bottom, the number of first diversion pipes corresponding to the plurality of cavity units increases sequentially.

[0010] Furthermore, along the top-down direction, the number of injection holes on the injection baffles corresponding to the multiple cavity units increases successively; and / or, the sizes of the injection holes on each injection baffle are the same, and along the top-down direction, the areas of the injection holes on the injection baffles corresponding to the multiple cavity units increase successively.

[0011] Furthermore, the microchannel heat exchanger also includes a plurality of drainage tubes, which are arranged one-to-one corresponding to the plurality of cavity units; both ends of each drainage tube are connected to the cavity below the injection partition in the corresponding cavity unit, and the pipe openings of each group of first diversion tubes for connecting with the connecting cavity are located between the two ends of the corresponding drainage tube.

[0012] Furthermore, the microchannel heat exchanger also includes a liquid separator, which is connected to the refrigerant injection port of each cavity unit respectively to provide refrigerant to each cavity unit respectively.

[0013] Furthermore, the microchannel heat exchanger also includes a plurality of second shunt tubes, which are arranged one-to-one corresponding to the plurality of refrigerant injection ports, and each second shunt tube is located between the liquid separator and the corresponding refrigerant injection port to connect the liquid separator with each refrigerant injection port respectively.

[0014] Furthermore, the second shunt pipe includes a shunt capillary and a shunt connecting pipe connected to each other, the shunt capillary is connected to the liquid distributor, and the shunt connecting pipe is connected to the corresponding refrigerant injection port.

[0015] Furthermore, the microchannel heat exchanger further comprises: a plurality of isolation components, which are arranged in the header at intervals along the vertical direction to divide the header into a plurality of cavity units arranged in sequence from top to bottom.

[0016] Furthermore, each isolation component is movably arranged relative to the manifold, so that the number of first flow diversion pipes corresponding to the corresponding cavity unit can be adjusted by adjusting the position of the isolation component.

[0017] According to another aspect of the present invention, an air conditioning device is provided, including an air conditioning indoor unit and an air conditioning outdoor unit. A heat exchanger is provided in the air conditioning outdoor unit, and the heat exchanger is the above-mentioned microchannel heat exchanger.

[0018] Applying the technical scheme of the present invention, the microchannel heat exchanger of the present invention includes a vertically placed collecting pipe, the collecting pipe includes a cavity unit having a connecting cavity and a group of first branch pipes connected to the connecting cavity, the cavity unit includes an injection baffle and a refrigerant injection port, the injection baffle is arranged in the connecting cavity, and divides the connecting cavity into a first cavity part and a second cavity part from top to bottom, the refrigerant injection port is located in the first cavity part above the injection baffle, a group of first branch pipes are all connected to the second cavity part of the connecting cavity located below the injection baffle, and a plurality of injection holes arranged at intervals are arranged on the injection baffle, so that the refrigerant reaching the first cavity part above the injection baffle from the refrigerant injection port is sprayed from top to bottom through the injection holes. In this way, the setting of the injection baffle enables the refrigerant in the cavity unit of the collecting pipe to be evenly sprayed in a direction perpendicular to the vertical direction, making the left and right diversion of the refrigerant more uniform, so that the refrigerant can evenly enter the first diversion pipe through the multiple laterally distributed holes at the pipe mouth of the first diversion pipe connected to the connecting cavity. In addition, it can also increase the amount of refrigerant entering the first diversion pipe in the same time period, thereby solving the problem of uneven diversion of the microchannel heat exchanger in the top-outlet air conditioner in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0020] Figure 1 The overall structural schematic diagram of an embodiment of a microchannel heat exchanger according to the present invention is shown;

[0021] Figure 2 Shows Figure 1 A partial structural schematic diagram of a microchannel heat exchanger shown; and

[0022] Figure 3 Shows Figure 1 Schematic diagram of the structure of the injection baffle in the microchannel heat exchanger shown.

[0023] The above drawings include the following reference numerals:

[0024] 1. Collecting pipe; 10. Cavity unit; 11. First cavity part; 12. Second cavity part; 13. Refrigerant injection port; 2. Isolation component; 3. First shunt pipe; 4. Injection partition; 41. Plate body; 42. Injection hole; 5. Second shunt pipe; 51. shunt connecting pipe; 52. shunt capillary; 6. Liquid distributor; 7. Drainage tube; 71. First end; 72. Second end. DETAILED DESCRIPTION

[0025] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0026] like Figures 1 to 3 As shown, the present invention provides a microchannel heat exchanger, including a collecting pipe 1, the collecting pipe 1 includes a cavity unit 10 with a connecting cavity and a group of first branch pipes 3 connected with the connecting cavity, the collecting pipe 1 is placed vertically, the cavity unit 10 includes: an injection baffle 4 and a refrigerant injection port 13, the injection baffle 4 is arranged in the connecting cavity, the refrigerant injection port 13 is located above the injection baffle 4, and a group of first branch pipes 3 are all connected with the cavity of the connecting cavity located below the injection baffle 4; wherein, a plurality of injection holes 42 arranged at intervals are arranged on the injection baffle 4, so that the refrigerant reaching the top of the injection baffle 4 from the refrigerant injection port 13 is sprayed downward through the injection holes 42.

[0027] The microchannel heat exchanger of the present invention includes a vertically placed collecting pipe 1, the collecting pipe 1 includes a cavity unit 10 with a connecting cavity and a group of first diverter pipes 3 connected to the connecting cavity, the cavity unit 10 includes an injection baffle 4 and a refrigerant injection port 13, the injection baffle 4 is arranged in the connecting cavity, and divides the connecting cavity from top to bottom into a first cavity part 11 and a second cavity part 12, the refrigerant injection port 13 is located in the first cavity part 11 above the injection baffle 4, a group of first diverter pipes 3 are all connected to the second cavity part 12 of the connecting cavity located below the injection baffle 4, and a plurality of injection holes 42 arranged at intervals are arranged on the injection baffle 4, so that the refrigerant reaching the first cavity part 11 above the injection baffle 4 from the refrigerant injection port 13 is sprayed from top to bottom through the injection holes 42. In this way, the setting of the injection baffle 4 enables the refrigerant in the cavity unit 10 of the collecting pipe 1 to be evenly sprayed in a direction perpendicular to the vertical direction, making the left and right diversion of the refrigerant more uniform, so that the refrigerant can evenly pass through the multiple transversely distributed holes at the pipe mouth of the first diversion pipe 3 connected to the connecting cavity and enter the first diversion pipe 3. In addition, it can also increase the amount of refrigerant entering the first diversion pipe 3 in the same time period, thereby solving the problem of uneven diversion of the microchannel heat exchanger in the air conditioner of the top outlet type in the prior art.

[0028] Specifically, the first shunt pipe 3 is a flat tube, and the width direction of the tube opening connecting the flat tube and the connecting cavity is arranged perpendicular to the vertical direction. Along the direction perpendicular to the vertical direction, the tube opening of the flat tube includes a plurality of through holes arranged in sequence at intervals to connect the flat tube and the connecting cavity.

[0029] Preferably, there are a plurality of cavity units 10, and the plurality of cavity units 10 are arranged in sequence from top to bottom. Along the direction from top to bottom, the manifold 1 is divided into a plurality of cavity units 10 separated from each other.

[0030] Furthermore, along the direction from top to bottom, the number of first diversion pipes 3 corresponding to the plurality of cavity units 10 increases sequentially.

[0031] Along the top-down direction, each first diversion pipe 3 is arranged at intervals in sequence. For the top-outlet type, the wind speed is high at the top and low at the bottom. During the heating cycle, the cavity unit 10 located above the collecting pipe 1 can evaporate a large amount of refrigerant, and the number of first diversion pipes 3 required is also small. Therefore, along the top-down direction, the number of first diversion pipes 3 should be increased successively.

[0032] As the number of the first branch pipes 3 increases from top to bottom, the total area of ​​the injection holes 42 on the corresponding injection baffles 4 also increases in order to improve the uniformity of the refrigerant distribution.

[0033] Optionally, the number of injection holes 42 on the injection partition plate 4 corresponding to the multiple cavity units 10 increases successively along the top-down direction; and / or, the sizes of the injection holes 42 on each injection partition plate 4 are the same, and the areas of the injection holes 42 on the injection partition plate 4 corresponding to the multiple cavity units 10 increase successively along the top-down direction.

[0034] The same size of the injection holes 42 on each injection baffle 4 means that the shapes and sizes of the injection holes 42 on the same injection baffle 4 are the same.

[0035] Optionally, the injection holes 42 on the injection baffle 4 may be in a circular, square, elliptical or other shapes.

[0036] The injection baffle 4 includes a plate body 41 and a plurality of injection holes 42 arranged on the plate body 41. The shape of the plate body 41 is arranged corresponding to the shape of the cross section of the connecting cavity of the cavity unit 10. The arrangement of the injection holes 42 on the injection baffle 4 is similar to the multi-hole arrangement at the shower head. From top to bottom, by arranging the difference in the number of injection holes 42 of each injection baffle 4, the difference in the size and area of ​​the injection holes 42, and the difference in the number of each group of first diverter pipes 3, the difference in the upper and lower wind speeds in the upper air outlet type is dealt with, thereby achieving uniform distribution and diversion of the refrigerant in the manifold 1.

[0037] Preferably, the microchannel heat exchanger also includes a plurality of drainage tubes 7, and the plurality of drainage tubes 7 are arranged one-to-one corresponding to the plurality of cavity units 10; both ends of each drainage tube 7 are connected to the cavity below the injection baffle 4 in the corresponding cavity unit 10, and the pipe openings of each group of first diversion tubes 3 for connecting with the connecting cavity are located between the two ends of the corresponding drainage tube 7.

[0038] The provision of the drainage tube 7 can introduce the liquid refrigerant deposited at the bottom of the second cavity portion 12 of the communicating cavity into the upper portion of the second cavity portion 12, so that the liquid refrigerant re-enters the circulation to improve the uniformity of the refrigerant diversion.

[0039] Liquid refrigerant is stored at the bottom of the drainage tube 7. Since the flow velocity at the bottom is very small and the flow velocity at the top is relatively large, according to the Bernoulli equation, a pressure difference is generated due to the flow velocity difference, and the liquid refrigerant at the bottom of the second cavity portion 12 will be introduced into the upper part of the second cavity portion 12 for recirculation.

[0040] Both ends of the drainage tube 7 are connected to the second cavity portion 12 located below the injection partition 4, the first end 71 of the drainage tube 7 is the inlet, and the second end 72 is the outlet. The first end 71 is arranged below all the first diversion tubes 3 in the corresponding second cavity portion 12, and the second end 72 is arranged above all the first diversion tubes 3 in the corresponding second cavity portion 12.

[0041] Specifically, the drainage tube 7 can be set with different tube diameters according to the position of the corresponding cavity unit 10 .

[0042] like Figure 1 As shown, the microchannel heat exchanger further includes a liquid separator 6, which is respectively connected to the refrigerant injection port 13 of each cavity unit 10 to provide refrigerant to each cavity unit 10. When the air conditioner is in a heating cycle, the refrigerant flows into the manifold 1 through the liquid separator 6.

[0043] Specifically, the microchannel heat exchanger also includes a plurality of second diverter tubes 5, which are arranged one-to-one corresponding to the plurality of refrigerant injection ports 13, and each second diverter tube 5 is located between the liquid separator 6 and the corresponding refrigerant injection port 13 to connect the liquid separator 6 with each refrigerant injection port 13 respectively.

[0044] Specifically, the second flow splitter 5 includes a flow splitter capillary 52 and a flow splitter connecting tube 51 which are connected to each other. The flow splitter capillary 52 is connected to the liquid distributor 6 , and the flow splitter connecting tube 51 is connected to the corresponding refrigerant injection port 13 .

[0045] A shunt capillary 52 is arranged one-to-one between the liquid distributor 6 and each cavity unit 10. The length of the shunt capillary 52 corresponding to each cavity unit 10 is also set according to the best matching shunt effect. From top to bottom, the length of each shunt capillary 52 increases successively. The longer the length of the shunt capillary 52, the greater the flow resistance of the refrigerant, so that the amount of refrigerant entering each cavity unit 10 is reduced successively to adapt to the difference in air volume in the upper and lower directions, and meet the requirements of the evaporation speed and evaporation amount of the refrigerant in each first shunt tube 3 pair.

[0046] The shunt connecting pipe 51 is arranged on the collecting pipe 1 and is connected to the refrigerant injection port at the first cavity part 11 above the corresponding injection partition 4. By shunting the shunt connecting pipe 51 above the corresponding cavity unit 10, the part of the connecting cavity located below the shunt connecting pipe 51 can store refrigerant during the refrigeration cycle, thereby solving the problem of refrigerant amount mismatch between the refrigeration cycle and the heating cycle without adding an external liquid storage tank.

[0047] Specifically, the microchannel heat exchanger further includes: a plurality of isolation components 2, which are arranged in the header 1 at intervals along the vertical direction to divide the header 1 into a plurality of cavity units 10 arranged sequentially from top to bottom.

[0048] Specifically, the isolation component 2 is a solid isolation plate to separate the cavity units 10 from each other.

[0049] Optionally, each isolation component 2 is movably arranged relative to the manifold 1 , so that the number of first branch pipes 3 corresponding to the corresponding cavity unit 10 can be adjusted by adjusting the position of the isolation component 2 .

[0050] The present invention also provides an air conditioning device, including an air conditioning indoor unit and an air conditioning outdoor unit. A heat exchanger is arranged in the air conditioning outdoor unit, and the heat exchanger is the above-mentioned microchannel heat exchanger.

[0051] Specifically, the air-conditioning outdoor unit in the air-conditioning equipment of the present invention is a top-outlet type. After the top-outlet type air-conditioning outdoor unit adopts the microchannel heat exchanger of the present invention, it can well solve the problem of uneven upper and lower flow diversion and uneven left and right flow diversion of the collecting pipe 1 caused by the microchannel heat exchanger being arranged in the top-outlet type, so that the microchannel heat exchanger has a good heat exchange effect.

[0052] In the air conditioning device having the microchannel heat exchanger of the present invention, the working process of the microchannel heat exchanger is as follows:

[0053] During the heating cycle of the air conditioner, the refrigerant flows in the direction of compressor → indoor unit of the air conditioner → outdoor unit of the air conditioner → compressor. The refrigerant condenses and releases heat in the indoor unit of the air conditioner, and then evaporates and absorbs heat in the outdoor unit of the air conditioner to heat the indoor air. In the microchannel heat exchanger of the outdoor unit of the air conditioner, the refrigerant enters the connecting cavity of each cavity unit 10 of the manifold 1 through the liquid distributor 6, the shunt capillary 52 and the shunt connecting pipe 51, and then flows out through multiple first shunt pipes 3. First, the amount of refrigerant entering the connecting cavity of each cavity unit 10 is adjusted through the shunt capillary 52. ​​The shunt capillary 52 corresponding to each cavity unit 10 can be set to different lengths to adjust the flow rate of the refrigerant more finely. The refrigerant enters the first cavity part 11 above each cavity unit 10 through the shunt connecting pipe 51, and is sprayed downward through the spray partition 4 with the spray hole 42, so that each first shunt pipe 3 can obtain a relatively uniform amount of refrigerant.

[0054] In addition, the liquid refrigerant deposited at the bottom of the communicating cavity can be guided to the top of the second cavity portion 12 through the drainage pipe 7 for recirculation to prevent part of the liquid refrigerant from being deposited.

[0055] During the refrigeration cycle of the air conditioner, the refrigerant flows in the direction of compressor → air conditioner outdoor unit → air conditioner indoor unit → compressor, and the refrigerant condenses and releases heat in the air conditioner outdoor unit, and then reaches the air conditioner indoor unit to evaporate and absorb heat to cool the indoor air. Among them, in the microchannel heat exchanger of the air conditioner outdoor unit, the refrigerant enters the corresponding connecting cavity from each first shunt pipe 3, and only when the height of the refrigerant entering the connecting cavity is higher than the height of the shunt connecting pipe 51, the liquid refrigerant can be discharged to the outside of the manifold 1 through the shunt connecting pipe 51. Since the shunt connecting pipe 51 is located above the connecting cavity, the space below the connecting cavity in the manifold 1 can store liquid refrigerant, thereby solving the problem of mismatch of refrigerant quantity during the refrigeration cycle and the heating cycle without adding an external liquid storage tank.

[0056] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0057] (1) By setting the injection baffle 4, the uniformity of the refrigerant diversion along the direction perpendicular to the vertical is improved, and the heat exchange effect of the heating cycle process is improved, so that the refrigerant can evenly enter the flat tube through the multiple holes distributed laterally at the tube mouths of each flat tube, thereby solving the problem of refrigerant diversion along the direction perpendicular to the vertical in the microchannel heat exchanger during the heating cycle process.

[0058] (2) By setting the drainage pipe 7, the uniformity of the refrigerant diversion in the vertical direction is improved, and the gas-liquid stratification phenomenon that occurs to a certain extent due to the influence of gravity on the refrigerant in the gas-liquid two-phase state is reduced. The liquid refrigerant is evenly distributed from top to bottom, so that the refrigerant flow entering each flat tube arranged from top to bottom tends to be uniform, which solves the problem of refrigerant diversion in the vertical direction of the microchannel heat exchanger during the heating cycle and improves the heat exchange effect of the microchannel heat exchanger.

[0059] (3) The problem of uneven heat exchange in the microchannel heat exchanger caused by the difference in upper and lower wind speeds in the top-outlet model has been solved.

[0060] (4) The provision of the refrigerant injection port and the flow-dividing connecting pipe 51 solves the problem of the mismatch of the refrigerant amount during the refrigeration cycle and the heating cycle.

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A microchannel heat exchanger, comprising a header (1), wherein the header (1) comprises a cavity unit (10) having a connecting cavity and a group of first flow diversion pipes (3) connected to the connecting cavity, characterized in that: The manifold (1) is placed vertically, and the cavity unit (10) comprises: An injection baffle (4) and a refrigerant injection port (13), wherein the injection baffle (4) is arranged in the connecting cavity, the refrigerant injection port (13) is located above the injection baffle (4), and the group of first shunt pipes (3) are all connected to the cavity of the connecting cavity located below the injection baffle (4); The injection baffle (4) is provided with a plurality of injection holes (42) arranged at intervals, so that the refrigerant reaching the top of the injection baffle (4) from the refrigerant injection port (13) is sprayed downward through the injection holes (42); The microchannel heat exchanger further comprises a plurality of isolation components (2), wherein the plurality of isolation components (2) are arranged in the header (1) at intervals in the vertical direction so as to divide the header (1) into a plurality of cavity units (10) arranged in sequence from top to bottom; Each of the isolation components (2) is a solid isolation plate; The injection baffle (4) corresponding to each of the chamber units (10) is located above the corresponding group of first diversion pipes (3).

2. The microchannel heat exchanger according to claim 1, characterized in that: Along the direction from top to bottom, the number of the first flow diversion pipes (3) corresponding to the plurality of cavity units (10) increases successively.

3. The microchannel heat exchanger according to claim 1, characterized in that: Along the direction from top to bottom, the number of the injection holes (42) on the injection baffle (4) corresponding to the plurality of cavity units (10) increases successively; and / or, The sizes of the injection holes (42) on each of the injection baffles (4) are the same, and the areas of the injection holes (42) on the injection baffles (4) corresponding to the plurality of cavity units (10) increase sequentially from top to bottom.

4. The microchannel heat exchanger according to claim 1, characterized in that: The microchannel heat exchanger further comprises a plurality of drainage tubes (7), and the plurality of drainage tubes (7) are arranged in one-to-one correspondence with the plurality of cavity units (10); both ends of each of the drainage tubes (7) are connected to the cavity below the injection baffle (4) in the corresponding cavity unit (10), and the pipe opening of each group of the first diversion tubes (3) for connecting with the connecting cavity is located between the two ends of the corresponding drainage tube (7).

5. The microchannel heat exchanger according to claim 1, characterized in that: The microchannel heat exchanger further comprises a liquid separator (6), wherein the liquid separator (6) is respectively connected to the refrigerant injection port (13) of each of the cavity units (10) so as to respectively provide refrigerant to each of the cavity units (10).

6. The microchannel heat exchanger according to claim 5, characterized in that: The microchannel heat exchanger also includes a plurality of second shunt tubes (5), and the plurality of second shunt tubes (5) are arranged one-to-one corresponding to the plurality of refrigerant injection ports (13). Each of the second shunt tubes (5) is located between the liquid separator (6) and the corresponding refrigerant injection port (13) so as to connect the liquid separator (6) with each of the refrigerant injection ports (13) respectively.

7. The microchannel heat exchanger according to claim 6, characterized in that: The second flow splitter (5) comprises a flow splitter capillary (52) and a flow splitter connecting tube (51) which are connected to each other, the flow splitter capillary (52) is connected to the liquid distributor (6), and the flow splitter connecting tube (51) is connected to the corresponding refrigerant injection port (13).

8. The microchannel heat exchanger according to claim 1, characterized in that: Each of the isolation components (2) is movably arranged relative to the manifold (1), so that the number of the first flow distribution pipes (3) corresponding to the corresponding cavity unit (10) can be adjusted by adjusting the position of the isolation component (2).

9. An air conditioning device, comprising an air conditioning indoor unit and an air conditioning outdoor unit, wherein a heat exchanger is arranged in the air conditioning outdoor unit, characterized in that: The heat exchanger is the microchannel heat exchanger according to any one of claims 1 to 8.

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