Integrated separation structure and micro-channel heat exchanger

Abstract

The application belongs to the field of refrigeration technology and equipment, and relates to an integrated distribution structure and a micro-channel heat exchanger. A single set of pipe distribution structure comprises an outer sleeve, a middle sleeve and an inner sleeve; the outer sleeve, the middle sleeve and the inner sleeve are coaxially nested; and the outer sleeve, the middle sleeve and the inner sleeve are respectively provided with an inlet hole; a hollow inner cavity of the inner sleeve constitutes a rectifying section, and a third inlet hole is in communication with the rectifying section; a distribution cavity is formed between the top of the inner sleeve and an end cover at the upper end, the middle sleeve is provided with a distribution flow path, and two ends of each distribution flow path are respectively an inlet and an outlet; an outlet of a groove is in communication with an outlet hole of the outer sleeve; the header is provided with an entering hole and a flat tube groove, the flat tube groove is in communication with the entering hole and the outlet hole through the entering hole, and one end of a flat tube is inserted into the flat tube groove. The integrated distribution structure and the micro-channel heat exchanger can uniformly distribute gas-liquid two-phase fluid, and are not limited by the number of heat exchange branches.

Description

Technical Field

[0001] This invention belongs to the field of refrigeration technology and equipment, specifically relating to an integrated liquid separation structure and a microchannel heat exchanger. Background Technology

[0002] At the evaporator inlet, the refrigerant is in a two-phase state with a complex flow pattern, making it difficult to achieve uniform flow distribution and maximize the evaporator's heat transfer potential. Traditional copper tube heat exchangers typically employ perforated, conical, or reflective distributors. The principle is that the inlet pipe enters a large mixing chamber, becoming a uniform mist flow, which is then distributed to various heat exchange branches by capillary tubes. Furthermore, a straight pipe section is usually installed before the inlet pipe to eliminate the momentum influence of the preceding pipes, thus acting as a flow rectifyer. However, in microchannel heat exchangers, the number of microchannel heat exchange branches and capillary tubes increases accordingly. This leads to complex distributor manufacturing processes, higher costs, and the risk of pipe rupture.

[0003] Therefore, the existing gas-liquid two-phase flow uniform distribution technology, especially the technology that can be adapted to microchannel heat exchangers, needs further research and improvement. Summary of the Invention

[0004] This invention proposes an integrated liquid distribution structure and microchannel heat exchanger, which can distribute gas-liquid two-phase fluids relatively evenly and is not limited by the number of heat exchange branches.

[0005] The technical solution of the present invention to solve the above problems is:

[0006] Firstly, this invention proposes a single-tube liquid distribution structure, which is characterized by:

[0007] It includes inlet pipe, outer sleeve, middle sleeve, inner sleeve, end cap, manifold, and flat pipe;

[0008] The outer sleeve, middle sleeve, and inner sleeve are coaxially nested from the outside in;

[0009] The outer sleeve has a first inlet hole and several outlet holes on its tube wall. The first inlet hole is located at the bottom of the outer sleeve. The first inlet hole is connected to the inlet pipe. The middle sleeve has a second inlet hole on its tube wall, and the inner sleeve has a third inlet hole on its tube wall. The first inlet hole, the second inlet hole, and the third inlet hole are connected in sequence.

[0010] The upper and lower ends of the outer sleeve are sealed by end caps, and the hollow inner cavity of the inner sleeve forms a rectifier section, with the third inlet hole connected to the rectifier section. The top of the inner sleeve is lower than the top of the outer sleeve, creating a distribution cavity between the top of the inner sleeve and the upper end cap.

[0011] The middle sleeve has several hollowed-out channels. The hollowed-out channels cooperate with the inner wall of the outer sleeve and the outer wall of the inner sleeve to form a liquid distribution path. Each liquid distribution path has an inlet and an outlet at its two ends. The inlet of the channel is located at the top of the middle sleeve and is connected to the distribution chamber. The outlet of the channel is connected to the outlet hole of the outer sleeve.

[0012] The manifold is provided with an inlet hole and a flat tube groove. The flat tube groove is connected to the outlet hole through the inlet hole. One end of the flat tube is inserted into the flat tube groove. The flat tube has several microchannels inside.

[0013] Two-phase refrigerant enters through the inlet pipe and sequentially flows through the first, second, and third inlet holes into the rectifying section. Within the rectifying section, it flows upwards to the distribution chamber, which connects to the channel inlet of the middle sleeve. The refrigerant is then evenly distributed into each channel and flows along the channels to the outlet hole of the outer sleeve. From the outlet hole, the refrigerant enters the inlet hole of the manifold and is subsequently distributed into the internal microchannels of the flat tube, thus completing the uniform distribution of the two-phase refrigerant.

[0014] Furthermore, one end of the aforementioned channel is an inlet, and the other end is connected to a two-way port. The outlet of the two-way port is connected to a second channel, and the end of the second channel is connected to the outlet hole of the outer sleeve.

[0015] Furthermore, the inlet dimensions of each of the above channels are the same and are evenly distributed circumferentially, thereby ensuring that the refrigerant in the distribution chamber enters each channel evenly; the inner diameter of the outer sleeve is equal to or slightly larger than the outer diameter of the middle sleeve, and the inner diameter of the middle sleeve is equal to or slightly larger than the outer diameter of the inner sleeve, which facilitates nested assembly.

[0016] Furthermore, the aforementioned manifold also includes a side plate. One side of the manifold is curved and fits with the outer surface of the outer sleeve, while the other side is flat. The side plate is used to seal the other side of the flat pipe groove.

[0017] Secondly, this invention proposes a double-tube liquid distribution structure, which is unique in that:

[0018] It includes an inlet pipe, an outer sleeve, a middle sleeve, an inner sleeve, an end cap, a connecting clamp, a second outer sleeve, a second middle sleeve, and a second inner sleeve;

[0019] The outer sleeve, middle sleeve, and inner sleeve are coaxially nested from the outside to the inside to form the first sleeve; the second outer sleeve, second middle sleeve, and second inner sleeve are coaxially nested from the outside to the inside to form the second sleeve.

[0020] The outer sleeve has a first inlet hole and several outlet holes on its tube wall. The first inlet hole is located at the bottom of the outer sleeve. The first inlet hole is connected to the inlet pipe. The middle sleeve has a second inlet hole on its tube wall, and the inner sleeve has a third inlet hole on its tube wall. The first inlet hole, the second inlet hole, and the third inlet hole are connected in sequence.

[0021] The upper and lower ends of the outer sleeve are sealed by end caps, and the hollow inner cavity of the inner sleeve forms a rectifier section, with the third inlet hole connected to the rectifier section. The top of the inner sleeve is lower than the top of the outer sleeve, creating a distribution cavity between the top of the inner sleeve and the upper end cap.

[0022] The middle sleeve has several hollowed-out first channels. The hollowed-out first channels cooperate with the inner wall of the outer sleeve and the outer wall of the inner sleeve to form a liquid distribution path. The two ends of each liquid distribution path are the inlet and the outlet, respectively. The inlet of the first channel is located at the top of the middle sleeve and is connected to the distribution chamber; the outlet of the first channel is connected to the outlet hole of the outer sleeve.

[0023] The second outer sleeve has several fourth inlet holes and fourth outlet holes. Each fourth inlet hole is connected to one outlet hole of the outer sleeve through a connecting clamp. The second middle sleeve has several hollowed-out channels. The hollowed-out channels cooperate with the inner wall of the second outer sleeve and the outer wall of the second inner sleeve to form a liquid distribution path. The two ends of each liquid distribution path are the inlet and the outlet, respectively. The inlet of the liquid distribution path is connected to the fourth inlet hole, and the outlet of the liquid distribution path is connected to the fourth outlet hole.

[0024] Two-phase refrigerant enters from the inlet pipe and sequentially enters the rectifier section through the first inlet hole, the second inlet hole, and the third inlet hole. In the rectifier section, it flows upward to the distribution chamber. The distribution chamber is connected to the channel inlet of the middle layer sleeve, and the refrigerant is evenly distributed into each channel. It flows along the channel to the outlet hole of the outer layer sleeve. The refrigerant enters the fourth inlet hole of the second outer layer sleeve through the connecting clamp from the outlet hole. The refrigerant is evenly distributed into each channel and flows along the channel to the fourth outlet hole of the second outer layer sleeve.

[0025] Furthermore, it also includes a manifold and a flat tube. The manifold is provided with an inlet hole and a flat tube groove. The flat tube groove is connected to the fourth outlet hole through the inlet hole. One end of the flat tube is inserted into the flat tube groove. The flat tube has several microchannels inside.

[0026] The refrigerant flowing out of the fourth outlet hole of the second outer sleeve enters the inlet hole of the manifold and is then distributed into the internal microchannels of the flat tube, thereby completing the uniform distribution of the two-phase refrigerant.

[0027] Furthermore, the number of first channels on the aforementioned intermediate sleeve is four.

[0028] Furthermore, the channels on the second intermediate sleeve include the first channel of the second sleeve and the second channel of the second sleeve.

[0029] The fourth inlet hole of the second outer sleeve is connected to the center of the first channel of the second sleeve on the second middle sleeve. The first channel of the second sleeve at the connection point is divided into two opposite directions in the horizontal direction. The first channel of the second sleeve is connected to the second channel of the second sleeve through a two-way port, which is located at the center of the second channel of the second sleeve. The second channel of the second sleeve at the connection point is divided into two opposite directions in the horizontal direction. The channel port at the end of the second channel of the second sleeve is connected to the fourth outlet hole of the second outer sleeve.

[0030] Furthermore, the cross-sectional area of ​​the fourth inlet hole is greater than or equal to the flow cross-sectional area of ​​the first channel of the second sleeve, the flow cross-sectional area of ​​the first channel of the second sleeve is greater than or equal to the flow cross-sectional area of ​​the second channel of the second sleeve, and the flow cross-sectional area of ​​the second channel of the second sleeve is greater than or equal to the flow cross-sectional area of ​​the fourth outlet hole.

[0031] Furthermore, the inlet dimensions of the first channels on the aforementioned middle layer sleeve are all the same and are evenly distributed along the circumference of the middle layer sleeve, thereby ensuring that the refrigerant in the distribution chamber enters each channel evenly.

[0032] Thirdly, the present invention also proposes a microchannel heat exchanger, which is characterized by including the above-mentioned single-tube liquid distribution structure or double-tube liquid distribution structure.

[0033] Advantages of this invention:

[0034] The gas-liquid distribution device provided by this invention has a simple process, is easy to manufacture, and has low processing cost; the built-in rectifier section and distribution cavity make the gas-liquid two-phase fluid distribution more stable and uniform; the channel structure formed by the sleeve makes it easy to combine with the two-part structure to form more branches, and can realize multi-branch integrated liquid distribution. Attached Figure Description

[0035] Figure 1 This is a diagram of a single-tube liquid separation structure.

[0036] Figure 2 This is a diagram of a single-sleeve sleeve assembly;

[0037] Figure 3 This is a structural diagram of an 8-channel liquid separator single-tube system;

[0038] Figure 4 This is a diagram of another 8-way liquid distribution sleeve structure;

[0039] Figure 5 This is a structural diagram of a 12-channel liquid distribution sleeve;

[0040] Figure 6 This is a diagram of a dual-tube, 16-way liquid distribution sleeve structure.

[0041] The figure shows: inlet pipe 1, outer sleeve 2, middle sleeve 3, inner sleeve 4, end cap 5, manifold 6, flat pipe 7, second middle sleeve 8, second inner sleeve 9, connecting clamp 10, second outer sleeve 11, first inlet hole 201, outlet hole 202, distribution cavity 203, second inlet hole 301, first channel 302, bi-section port 303, second channel 304, third inlet hole 401, rectifier section 402, inlet hole 601, flat pipe channel 602, side plate 603, fourth inlet hole 1101, fourth outlet hole 1102, first channel of the second sleeve 801, bi-section port of the second sleeve 802, second channel of the second sleeve 803, channel port 804. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0043] See Figure 1 A single-tube liquid distribution structure includes an inlet tube 1, an outer tube 2, a middle tube 3, an inner tube 4, an end cap 5, a manifold 6, and a flat tube 7.

[0044] The manifold 6 includes an inlet hole 601, a flat tube groove 602, and a side plate 603. One side of the manifold 6 is curved, fully fitting the outer surface of the outer sleeve 2, while the other side is flat. The inlet hole 601 of the manifold 6 penetrates through the manifold from the side, and the side plate 603 is used to seal the other side of the inlet hole 601. The flat tube groove 602 communicates with the inlet hole 601. The outer sleeve 2 has one inlet hole 201 and multiple outlet holes 202. The inlet hole 201 is connected to the inlet pipe 1, and the outlet holes 202 are connected to the inlet hole 601 of the manifold 6. The flat tube 7 is inserted into the flat tube groove 602 of the manifold 6 to a certain depth, and the flat tube 7 has several microchannels inside.

[0045] Example 1

[0046] Figure 2 This is a diagram of a single sleeve assembly, which includes an outer sleeve 2, a middle sleeve 3, an inner sleeve 4, and an end cap 5.

[0047] The outer sleeve 2, middle sleeve 3, and inner sleeve 4 are coaxially nested sequentially from the outside in. The inner diameter of the outer sleeve 2 is equal to or slightly larger than the outer diameter of the middle sleeve 3, and the inner diameter of the middle sleeve 3 is equal to or slightly larger than the outer diameter of the inner sleeve 4, facilitating nesting assembly. The middle sleeve 3 has several perforated first channels 302, which, together with the inner wall of the outer sleeve 2 and the outer wall of the inner sleeve 4, form liquid distribution channels. The two ends of each liquid distribution channel are the inlet and the outlet, respectively.

[0048] The upper and lower ends of the outer sleeve 2 are sealed by end caps 5 respectively. The hollow inner cavity of the inner sleeve 4 forms a rectifier section 402, and the third inlet hole 401 is connected to the rectifier section 402. The top of the inner sleeve 4 is lower than the top of the outer sleeve 2, so that the top of the inner sleeve 4 and the upper end cap 5 form a distribution cavity 203. The inlet of the first channel 302 is located at the top of the middle sleeve 3 and is connected to the distribution cavity 203. The outlet of the first channel 302 is connected to the outlet hole 202 of the outer sleeve 2.

[0049] In this embodiment, when the single-tube liquid distribution structure is working, the two-phase refrigerant enters from the inlet pipe 1 and sequentially enters the rectifier section 402 through the inlet hole 201 of the outer tube 2, the inlet hole 301 of the middle tube 3, and the inlet hole 401 of the inner tube 4. In the rectifier section 402, it flows upward to the distribution chamber 203. The distribution chamber 203 is connected to one end of the first channel 302 of the middle tube 3, and the refrigerant is evenly distributed into each of the first channels 302. The other end is connected to a split port 303, from which two paths are evenly split and enter two opposite directions in the second channel 304. The end of the second channel 304 is connected to the outlet hole 202 of the outer tube 2. The refrigerant enters the inlet hole 601 of the manifold 6 from the outlet hole 202, and is then distributed into the internal microchannels of the flat tube 7, thereby completing the uniform distribution of the two-phase refrigerant.

[0050] See Figure 2 One implementation of the channels on the middle layer sleeve 3 is as follows: there are four first channels 302, each first channel 302 includes a first vertical section and a horizontal section, the second channel 304 includes a second vertical section, one end of the first vertical section is the inlet of the first channel 302, the other end of the first vertical section is connected to one end of the horizontal section, the other end of the horizontal section is connected to the middle of the second vertical section through a two-way port 303, the two ends of the second vertical section extend horizontally to form horizontal extension sections, and the end of the horizontal extension section is the outlet, ultimately forming an 8-way liquid distribution structure.

[0051] See Figure 3Another implementation of the channels on the middle sleeve 3 is as follows: there are four first channels 302, each first channel 302 includes a first vertical section and a horizontal section, the second channel 304 includes a second vertical section, one end of the first vertical section is the inlet of the first channel 302, the other end of the first vertical section is connected to one end of the horizontal section, the other end of the horizontal section is connected to the middle of the second vertical section through the two-way port 303, and the two ends of the second vertical section are the outlets, thus forming an 8-way liquid distribution structure.

[0052] Figure 4 This is another implementation of the channel on the middle sleeve 3, and its... Figure 2 The differences between the channels shown are: the horizontal section of the first channel 302 is arranged in a different position in the axial direction, and the horizontal extension of the second vertical section in the second channel 304 is arranged in a different position in the axial direction.

[0053] Figure 5 The middle layer casing 3 and Figure 3 In comparison, the first channel 302 has six channels, forming 12 liquid distribution channels. It can be seen that by adjusting the channel arrangement on the middle sleeve 3, a liquid distribution structure with more branches can be achieved.

[0054] Example 2

[0055] See Figure 6 A double-tube liquid distribution structure, which is a double-tube 16-way liquid distribution sleeve structure, including an inlet tube 1, an outer sleeve 2, a middle sleeve 3, an inner sleeve 4, an end cap 5, a connecting clamp 10, a second outer sleeve 11, a second middle sleeve 8, and a second inner sleeve 9.

[0056] The outer sleeve 2, the middle sleeve 3, and the inner sleeve 4 are coaxially nested to form the first sleeve. The inner diameter of the outer sleeve 2 is equal to or slightly larger than the outer diameter of the middle sleeve 3, and the inner diameter of the middle sleeve 3 is equal to or slightly larger than the outer diameter of the inner sleeve 4, facilitating nesting assembly. The middle sleeve 3 has several hollowed-out channels, which, together with the inner wall of the outer sleeve 2 and the outer wall of the inner sleeve 4, form liquid distribution channels. The two ends of each liquid distribution channel are the inlet and the outlet, respectively.

[0057] The middle space of the inner sleeve 4 forms the rectifying section 402, and the top space of the outer sleeve 2 forms the distribution chamber 203. Two-phase refrigerant enters from the inlet pipe 1 and flows sequentially along the inlet hole 201 of the outer sleeve 2, the inlet hole 301 of the middle sleeve 3, and the inlet hole 401 of the inner sleeve 4 into the rectifying section 402. Within the rectifying section 402, it flows upwards to the distribution chamber 203. The distribution chamber 203 is connected to the channel 302 of the middle sleeve 3, and the refrigerant is evenly distributed into each channel 302, flowing along the channel 302 to the outlet hole 202 of the outer sleeve 2. One end of the channel 302 is connected to the distribution chamber 203, and the other end is connected to the outlet hole 202 of the outer sleeve 2. The refrigerant enters from the outlet hole 202 through the connecting clamp 10 into the fourth inlet hole 1101 of the second outer sleeve 11. The fourth inlet hole 1101 and the fourth outlet hole 1102 of the second outer sleeve 11 are evenly distributed in the axial direction, and the fourth inlet hole 1101 and the fourth outlet hole 1102 are 180° apart in the circumferential direction.

[0058] The second outer sleeve 11, the second middle sleeve 8, and the second inner sleeve 9 are coaxially nested from the outside in to form the second sleeve. The inner diameter of the second outer sleeve 11 is equal to or slightly larger than the outer diameter of the second middle sleeve 8, and the inner diameter of the second middle sleeve 8 is equal to or slightly larger than the outer diameter of the second inner sleeve 9, facilitating nesting assembly. The second middle sleeve 8 has several hollowed-out channels, which, together with the inner wall of the second outer sleeve 11 and the outer wall of the second inner sleeve 9, form liquid distribution channels. The two ends of each liquid distribution channel are the inlet and the outlet, respectively.

[0059] The flow path formed by the second sleeve repeats periodically in the axial direction, with its smallest repeating unit corresponding to one fourth inlet hole 1101 and four fourth outlet holes 1102 of the second outer sleeve 11. The fourth inlet hole 1101 of the second outer sleeve 11 is connected to the center of the first channel 801 of the second sleeve on the second middle sleeve 8, and the first channel 801 of the second sleeve at the connection point is divided into two opposite directions in the horizontal direction. The first channel 801 of the second sleeve is connected to the second channel 803 of the second sleeve through the bi-slit 802 of the second sleeve, which is located at the center of the second channel 803 of the second sleeve, and the second channel 803 of the second sleeve at the connection point is divided into two opposite directions in the horizontal direction. The channel port 804 of the second channel 803 of the second sleeve is connected to the fourth outlet hole 1102 of the second outer sleeve 11. The cross-sectional area of ​​the fourth inlet hole 1101 is greater than or equal to the flow cross-sectional area of ​​the first channel 801 of the second sleeve, the flow cross-sectional area of ​​the first channel 801 of the second sleeve is greater than or equal to the flow cross-sectional area of ​​the second channel 803 of the second sleeve, and the flow cross-sectional area of ​​the second channel 803 of the second sleeve is greater than or equal to the flow cross-sectional area of ​​the fourth outlet hole 1102.

[0060] The 16-channel liquid distribution sleeve structure implemented in this embodiment is a superior dual-sleeve liquid distribution structure provided by the present invention. The dual-sleeve liquid distribution structure has one more sleeve than the single-sleeve liquid distribution structure, but the design concept of its flow path is similar. The dual-sleeve liquid distribution structure can be used for liquid distribution in more branches.

[0061] Preferably, the above-mentioned double-tube liquid distribution structure further includes a manifold 6 and a flat tube 7. The manifold 6 includes an inlet hole 601, a flat tube groove 602, and a side plate 603. One side of the manifold 6 is arc-shaped, fully fitting the outer surface of the second outer sleeve 11, while the other side is flat. The inlet hole 601 of the manifold 6 penetrates the manifold from the side, and the side plate 603 is used to block the other side of the inlet hole 601. The flat tube groove 602 communicates with the inlet hole 601. The second outer sleeve 11 has a fourth inlet hole 1101 and multiple fourth outlet holes 1102. The fourth inlet hole 1101 is connected to the outlet hole 202 of the outer sleeve 2 via a connecting clamp 10, and the inlet hole 201 of the outer sleeve 2 is connected to the inlet pipe 1. The flat tube 7 is inserted into the flat tube groove 602 of the manifold 6 to a certain depth, and the flat tube 7 has several microchannels inside.

[0062] The present invention also proposes a microchannel heat exchanger, which includes any of the above-mentioned single-tube liquid distribution structure or double-tube liquid distribution structure. Thus, the microchannel heat exchanger also contains all the functions and effects of the above-mentioned liquid distribution structure, which will not be repeated here.

[0063] The above description is merely an embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related system fields, are similarly included within the scope of protection of the present invention.

Claims

1. A single casing pipe liquid distribution structure, characterized in that: comprising an inlet pipe (1), an outer casing pipe (2), a middle casing pipe (3), an inner casing pipe (4), an end cap (5), a manifold (6) and a flat pipe (7); the outer casing pipe (2), the middle casing pipe (3) and the inner casing pipe (4) are coaxially nested from outside to inside; the outer casing pipe (2) is provided with a first inlet hole (201) and a plurality of outlet holes (202) on the pipe wall, the first inlet hole (201) is located at the lower part of the outer casing pipe (2); the first inlet hole (201) is connected with the inlet pipe (1); the middle casing pipe (3) is provided with a second inlet hole (301) on the pipe wall, and the inner casing pipe (4) is provided with a third inlet hole (401) on the pipe wall, the first inlet hole (201), the second inlet hole (301) and the third inlet hole (401) are sequentially communicated; the upper and lower ends of the outer casing pipe (2) are respectively sealed by the end cap (5), the hollow inner cavity of the inner casing pipe (4) constitutes a rectifier section (402), the third inlet hole (401) is communicated with the rectifier section (402); the top of the inner casing pipe (4) is lower than the top of the outer casing pipe (2), so that a distribution cavity (203) is formed between the top of the inner casing pipe (4) and the end cap (5) at the upper end, the middle casing pipe (3) is provided with a plurality of hollow grooves, the hollow grooves cooperate with the inner wall of the outer casing pipe (2) and the outer wall of the inner casing pipe (4) to form liquid distribution flow paths, the two ends of each liquid distribution flow path are respectively an inlet and an outlet, the inlet of the liquid distribution flow path is located at the top of the middle casing pipe (3) and communicated with the distribution cavity (203); the outlet of the liquid distribution flow path is communicated with the outlet hole (202) of the outer casing pipe (2); the manifold (6) is provided with an entering hole (601) and a flat pipe groove (602), the flat pipe groove (602) is communicated with the outlet hole (202) through the entering hole (601), one end of the flat pipe (7) is inserted into the flat pipe groove (602), and the flat pipe (7) has a plurality of microchannels inside; the grooves include first grooves (302) and second grooves (304); one end of the first groove (302) is an inlet, the other end is connected with a two-way hole, the outlet of the two-way hole is connected with the second groove (304), and the end of the second groove (304) is communicated with the outlet hole (202) of the outer casing pipe (2). 2.The single casing pipe liquid distribution structure according to claim 1, characterized in that: the inlets of each first groove (302) are of the same size and are uniformly distributed in the circumferential direction; the inner diameter of the outer casing pipe (2) is equal to or slightly larger than the outer diameter of the middle casing pipe (3), and the inner diameter of the middle casing pipe (3) is equal to or slightly larger than the outer diameter of the inner casing pipe (4). 3.The single casing pipe liquid distribution structure according to claim 2, characterized in that: the manifold (6) further includes a side plate (603), one side of the manifold (6) is an arc surface matched with the outer surface of the outer casing pipe (2), and the other side is a flat surface, and the side plate (603) is used to block the other side of the flat pipe groove (602). 4.A double casing pipe liquid distribution structure, characterized in that: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The double-sleeve liquid distribution structure comprises an inlet pipe (1), an outer sleeve (2), a middle sleeve (3), an inner sleeve (4), an end cover (5), a connecting clamp block (10), a second outer sleeve (11), a second middle sleeve (8), and a second inner sleeve (9). The outer sleeve (2), the middle sleeve (3), and the inner sleeve (4) are coaxially nested from outside to inside to form a first sleeve; and the second outer sleeve (11), the second middle sleeve (8), and the second inner sleeve (9) are coaxially nested from outside to inside to form a second sleeve. The outer sleeve (2) is provided with a first inlet hole (201) and a plurality of outlet holes (202) on the wall thereof, the first inlet hole (201) is located at the lower part of the outer sleeve (2), the first inlet hole (201) is connected with the inlet pipe (1), the middle sleeve (3) is provided with a second inlet hole (301) on the wall thereof, the inner sleeve (4) is provided with a third inlet hole (401) on the wall thereof, and the first inlet hole (201), the second inlet hole (301), and the third inlet hole (401) are sequentially communicated. The upper and lower ends of the outer sleeve (2) are respectively sealed by the end cover (5), the hollow inner cavity of the inner sleeve (4) forms a rectifier section (402), the third inlet hole (401) is communicated with the rectifier section (402), and the top of the inner sleeve (4) is lower than the top of the outer sleeve (2), so that a distribution cavity (203) is formed between the top of the inner sleeve (4) and the end cover (5) at the upper end, The middle sleeve (3) is provided with a plurality of first hollow grooves (302), the first hollow grooves (302) are matched with the inner wall of the outer sleeve (2) and the outer wall of the inner sleeve (4) to form liquid distribution channels, the two ends of each liquid distribution channel are respectively an inlet and an outlet, the inlet of the first groove (302) is located at the top of the middle sleeve (3) and is communicated with the distribution cavity (203), and the outlet of the first groove (302) is communicated with the outlet hole (202) of the outer sleeve (2). The second outer sleeve (11) is provided with a plurality of fourth inlet holes (1101) and fourth outlet holes (1102), each fourth inlet hole (1101) is communicated with one outlet hole (202) of the outer sleeve (2) through the connecting clamp block (10), the second middle sleeve (8) is provided with a plurality of hollow grooves, the hollow grooves are matched with the inner wall of the second outer sleeve (11) and the outer wall of the second inner sleeve (9) to form liquid distribution channels, the two ends of each liquid distribution channel are respectively an inlet and an outlet, the inlet of the liquid distribution channel is communicated with the fourth inlet hole (1101), and the outlet of the liquid distribution channel is communicated with the fourth outlet hole (1102).

5. The double-sleeve liquid distribution structure according to claim 4, further comprising a header (6) and a flat tube (7), the header (6) is provided with an entering hole (601) and a flat tube groove (602), the flat tube groove (602) is communicated with the fourth outlet hole (1102) through the entering hole (601), one end of the flat tube (7) is inserted into the flat tube groove (602), and the flat tube (7) has a plurality of micro-channels inside.

6. The double-sleeve liquid distribution structure according to claim 4, further comprising a header (6) and a flat tube (7), the header (6) is provided with an entering hole (601) and a flat tube groove (602), the flat tube groove (602) is communicated with the fourth outlet hole (1102) through the entering hole (601), one end of the flat tube (7) is inserted into the flat tube groove (602), and the flat tube (7) has a plurality of micro-channels inside. ​ The first channel (302) on the middle layer sleeve (3) is four in number.

7. The double sleeve liquid distribution structure according to claim 6, characterized in that: The channel on the second middle layer sleeve (8) comprises a first channel (801) of the second sleeve and a second channel (803) of the second sleeve. The fourth inlet hole (1101) of the second outer layer sleeve (11) is in communication with the center of the first channel (801) of the second sleeve on the second middle layer sleeve (8), and the first channel (801) of the second sleeve is divided into two opposite directions in the horizontal direction at the communication position; the first channel (801) of the second sleeve is connected with the second channel (803) of the second sleeve through a two-way port, which is located at the center of the second channel (803) of the second sleeve, and the second channel (803) of the second sleeve is divided into two opposite directions in the horizontal direction at the communication position; the channel end port (804) at the end of the second channel (803) of the second sleeve is connected with the fourth outlet hole (1102) of the second outer layer sleeve (11).

8. The double sleeve liquid distribution structure according to claim 7, characterized in that: The cross-sectional area of the fourth inlet hole (1101) is greater than or equal to the flow cross-sectional area of the first channel (801) of the second sleeve, the flow cross-sectional area of the first channel (801) of the second sleeve is greater than or equal to the flow cross-sectional area of the second channel (803) of the second sleeve, and the flow cross-sectional area of the second channel (803) of the second sleeve is greater than or equal to the flow cross-sectional area of the fourth outlet hole (1102).

9. A micro-channel heat exchanger, characterized in that: It comprises the single sleeve liquid distribution structure according to any one of claims 1-3, or the double sleeve liquid distribution structure according to any one of claims 4-8.

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