Microchannel heat exchanger and heat pump system

Abstract

The present application provides a microchannel heat exchanger and a heat pump system. The microchannel heat exchanger comprises a first header (1), a second header (2) and a flat tube (3), wherein the flat tube (3) is connected between the first header (1) and the second header (2), and a plurality of isolation structures are arranged on the second header (2) at intervals along the axial direction, wherein the isolation structures are used to separate the second header (2) into a plurality of tube sections (4) with tube cavities (5) being isolated from each other, and each tube section (4) is connected to a refrigerant pipe (6). According to the microchannel heat exchanger and the heat pump system of the present application, the refrigerant distribution condition of the heat exchanger can be effectively improved when the number of flat tubes is large, thereby improving the heat exchange performance of the heat exchanger.

Description

Technical Field

[0001] The present application relates to the technical field of air conditioning, and in particular to a microchannel heat exchanger and a heat pump system. Background Art

[0002] When the microchannel heat exchanger is used as an evaporator, the inlet is generally gas-liquid two-phase, but the manifold of the traditional microchannel heat exchanger has no diversion measures. After entering the manifold, the gas-liquid two-phase stratification phenomenon is obvious, resulting in uneven distribution of refrigerant entering the flat tube and poor heat exchange performance of the heat exchanger.

[0003] The prior art provides a manifold distributor, in which a flat tube is inserted into the inlet part of the liquid manifold to reduce the pressure in the refrigerant flow channel in the liquid manifold, and at the same time, a refrigerant flow path is added outside the liquid manifold to cause the refrigerant in the liquid manifold to circulate. However, this solution is only applicable to the case where the number of flat tubes is small. When the number of flat tubes is large, the effect is not good. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present application is to provide a microchannel heat exchanger and a heat pump system, which can effectively improve the refrigerant distribution condition of the heat exchanger when the number of flat tubes is large and improve the heat exchange performance of the heat exchanger.

[0005] In order to solve the above problems, the present application provides a microchannel heat exchanger, including a first collecting pipe, a second collecting pipe and a flat tube, the flat tube is connected between the first collecting pipe and the second collecting pipe, and a plurality of isolation structures are arranged on the second collecting pipe at intervals along the axial direction. The isolation structure is used to divide the second collecting pipe into a plurality of pipe sections with isolated tube cavities, and each pipe section is connected to a refrigerant connecting pipe.

[0006] Preferably, a connecting pipe is arranged outside at least one pipe segment, a first end of the connecting pipe is connected to a first end of the pipe segment, and a second end of the connecting pipe is connected to a second end of the pipe segment.

[0007] Preferably, the isolation structure comprises an isolation block, the structure of the isolation block is adapted to the second header, a plurality of mounting grooves are arranged on the second header, and the isolation block is arranged in the mounting grooves.

[0008] Preferably, the isolation block includes a sealing portion and an embedded portion, a stop step is formed at the connection position of the sealing portion and the embedded portion, the mounting groove is a semicircular groove, the embedded portion is embedded in the second collecting pipe, the sealing portion is embedded in the semicircular groove, the stop step stops on the side walls at both ends of the semicircular groove, the sealing portion and the embedded portion cooperate with each other to separate the tube cavities on both sides of the isolation block.

[0009] Preferably, the isolation block includes a connecting hole and a flow hole that are interconnected, the refrigerant pipe is connected to the connecting hole, and the flow hole is connected to the tube cavity.

[0010] Preferably, the through-flow hole is an L-shaped hole, one end of the L-shaped hole is connected to the connecting hole, the other end of the L-shaped hole is connected to the lumen, and the cross-sectional area of ​​the connecting hole is larger than the cross-sectional area of ​​the through-flow hole.

[0011] Preferably, the isolation structure includes a sealing plate and a throttling plate, a throttling hole is provided on the throttling plate, a guide cavity is formed between the sealing plate and the throttling plate, the refrigerant pipe is connected with the guide cavity, the guide cavity is connected with the pipe cavity through the throttling plate, and the guide cavity is separated from the adjacent pipe section by the sealing plate.

[0012] Preferably, a mounting groove is provided on the second manifold, and the sealing plate and the throttle plate are both embedded in the mounting groove.

[0013] Preferably, the first header and the second header are arranged vertically, and the refrigerant pipe is connected to the bottom of the pipe section.

[0014] Preferably, the microchannel heat exchanger is a single-row heat exchanger, a double-row heat exchanger or a multi-row heat exchanger.

[0015] According to an embodiment of the present application, the heat pump system includes a microchannel heat exchanger, which is the microchannel heat exchanger mentioned above.

[0016] Preferably, the heat pump system further comprises a compressor, a first heat exchanger, a throttling device and a diverter which are connected in sequence, and the diverter comprises a plurality of diverter interfaces which are connected to the refrigerant pipes in a one-to-one correspondence.

[0017] The microchannel heat exchanger provided by the present application includes a first manifold, a second manifold and flat tubes, the flat tubes are connected between the first manifold and the second manifold, and a plurality of isolation structures are arranged on the second manifold along the axial interval, the isolation structure is used to separate the second manifold into a plurality of tube sections with isolated tube cavities, and each tube section is connected to a refrigerant pipe connection. The microchannel heat exchanger of the present application uses an isolation structure to separate the second manifold into a plurality of tube sections with isolated tube cavities. When the number of flat tubes is large, the plurality of flat tubes can be divided into a plurality of refrigerant flow areas through the isolated tube sections, reducing the flow of the refrigerant in each tube section, so that the refrigerant can be evenly distributed in each tube section, effectively improving the phenomenon of gas-liquid two-phase stratification, and improving the performance of the heat exchanger. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the three-dimensional structure of a microchannel heat exchanger according to an embodiment of the present application;

[0019] Figure 2 This is a schematic cross-sectional structural diagram of a microchannel heat exchanger according to the first embodiment of the present application;

[0020] Figure 3 This is a schematic cross-sectional structural diagram of a microchannel heat exchanger according to the first embodiment of the present application;

[0021] Figure 4It is a schematic diagram of the enlarged structure of the pipe section of the microchannel heat exchanger of the first embodiment of the present application;

[0022] Figure 5 It is a schematic diagram of the three-dimensional structure of the isolation block of the microchannel heat exchanger of the first embodiment of the present application;

[0023] Figure 6 A cross-sectional view of an isolation block of a microchannel heat exchanger according to the first embodiment of the present application;

[0024] Figure 7 This is a schematic cross-sectional structural diagram of a microchannel heat exchanger according to a second embodiment of the present application;

[0025] Figure 8 This is a schematic cross-sectional structural diagram of a microchannel heat exchanger according to a second embodiment of the present application;

[0026] Fig. 9 It is an enlarged structural schematic diagram of a pipe section of a microchannel heat exchanger according to the second embodiment of the present application;

[0027] Fig.10 A schematic diagram of the three-dimensional structure of a throttle plate of a microchannel heat exchanger according to the first embodiment of the present application;

[0028] Fig.11 This is a schematic diagram of the three-dimensional structure of the sealing plate of the microchannel heat exchanger of the first embodiment of the present application;

[0029] Fig.12 A schematic diagram of the three-dimensional structure of a double-row microchannel heat exchanger according to an embodiment of the present application;

[0030] Fig.13 This is a schematic diagram of the structure of the heat pump system according to an embodiment of the present application.

[0031] The reference numerals are:

[0032] 1. First manifold; 2. Second manifold; 3. Flat tube; 4. Pipe section; 5. Pipe cavity; 6. Refrigerant connecting pipe; 7. Connecting pipe; 8. Isolation block; 9. Mounting groove; 10. Sealing part; 11. Embedding part; 12. Stop step; 13. Connecting hole; 14. Through hole; 15. Sealing plate; 16. Throttle plate; 17. Throttle hole; 18. Guide cavity; 19. Microchannel heat exchanger; 20. Compressor; 21. First heat exchanger; 22. Throttle device; 23. Diverter; 24. Four-way valve. DETAILED DESCRIPTION

[0033] See also Figures 1 to 13As shown, according to an embodiment of the present application, the microchannel heat exchanger includes a first collecting tube 1, a second collecting tube 2 and a flat tube 3, the flat tube 3 is connected between the first collecting tube 1 and the second collecting tube 2, and a plurality of isolation structures are arranged on the second collecting tube 2 along the axial direction, and the isolation structure is used to separate the second collecting tube 2 into a plurality of pipe sections 4 isolated from each other by the pipe cavities 5, and each pipe section 4 is connected to a refrigerant connecting pipe 6.

[0034] The microchannel heat exchanger of the present application adopts an isolation structure to separate the second collecting pipe 2 into a plurality of pipe sections 4 with isolated tube cavities 5. When the number of flat tubes 3 is large, the plurality of flat tubes 3 can be divided into a plurality of refrigerant flow areas through the isolated pipe sections 4 to form a plurality of parallel flow paths, thereby reducing the flow of the refrigerant in each pipe section 4 and enabling the refrigerant to be evenly distributed in each pipe section 4, thereby effectively improving the phenomenon of gas-liquid two-phase stratification and improving the performance of the heat exchanger.

[0035] The first header 1 and the second header 2 are arranged vertically, and the refrigerant connecting pipe 6 is connected to the bottom of the pipe section 4 .

[0036] A connecting pipe 7 is provided outside at least one pipe segment 4, a first end of the connecting pipe 7 is connected to a first end of the pipe segment 4, and a second end of the connecting pipe 7 is connected to a second end of the pipe segment 4. For the pipe segment 4 provided with the connecting pipe 7, the connecting pipe 7 outside the pipe segment 4 can be used to form a circulation flow of the refrigerant in the flow path where the pipe segment 4 is located, so that the refrigerant entering each flat tube 3 corresponding to the pipe segment 4 is more evenly distributed.

[0037] Preferably, a connecting pipe 7 is provided outside each pipe section 4, so that each pipe section can form a circulating refrigerant flow, thereby ensuring that the flat tubes of the entire microchannel heat exchanger can achieve uniform distribution of the refrigerant, thereby maximizing the heat exchange performance of the heat exchanger.

[0038] In this embodiment, the microchannel heat exchanger includes N refrigerant pipes 6, N connecting pipes 7, N isolation structures, a first header 1, a second header 2, M flat tubes 3, end caps arranged at both ends of the headers, and fins located between adjacent flat tubes 3. The N isolation structures divide the second header 2 into N independent tube cavities 5, each isolation structure is connected to a refrigerant pipe 6, each tube cavity 5 is connected to a connecting pipe 7, and each connecting pipe 7 connects the upper and lower parts of the pipe section 4 where the connecting pipe 7 is located.

[0039] See also Figures 2 to 6As shown, according to the first embodiment of the present application, the isolation structure includes an isolation block 8, the structure of the isolation block 8 is adapted to the second manifold 2, a plurality of mounting grooves 9 are provided on the second manifold 2, and the isolation block 8 is provided in the mounting groove 9. By providing the mounting groove 9, the isolation block 8 can be conveniently installed on the second manifold 2, and the second manifold 2 can be effectively divided into a plurality of pipe sections 4, so that the structure is simpler and more convenient. The isolation block 8 and the mounting groove 9 of the second manifold 2 can be an interference fit, which can not only ensure that the connection structure between the isolation block 8 and the mounting groove 9 is stable and reliable, but also can utilize the interference fit to more conveniently achieve the sealing fit between the isolation block 8 and the second manifold 2. Preferably, in order to further improve the sealing performance between the isolation block 8 and the second manifold 2, the isolation block 8 and the mounting groove 9 can also be sealed by a sealant.

[0040] In this embodiment, the isolation block 8 includes a sealing portion 10 and an embedding portion 11, a stop step 12 is formed at the connection position of the sealing portion 10 and the embedding portion 11, the installation groove 9 is a semicircular groove, the embedding portion 11 is embedded in the second header 2, the sealing portion 10 is embedded in the semicircular groove, the stop step 12 stops on the two end side walls of the semicircular groove in the circumferential direction, and the sealing portion 10 and the embedding portion 11 cooperate with each other to separate the tube cavity 5 on both sides of the isolation block 8. The cross-section of the embedding portion 11 and the cross-section of the sealing portion 10 are both semicircular, and the radius of the embedding portion 11 is the same as the inner cavity radius of the second header 2, so as to ensure that the embedding portion 11 can be smoothly installed into the second header 2 from the semicircular groove, and the embedding portion 11 can be attached to the inner wall of the second header 2 to achieve a sealing match with the inner wall of the second header 2. The radius of the sealing portion 10 is the same as the outer diameter of the second header 2, which can ensure that the sealing portion 10 fits the groove walls on both sides of the semicircular groove and is flush with the outer wall of the second header 2, thereby forming a good appearance structure and conveniently utilizing the stop step formed between the sealing portion 10 and the embedded portion 11 to achieve the sealing fit between the isolation block 8 and the second header 2. The semicircular groove here means that on the outer surface of the second header 2, the mounting groove 9 is semicircular, and the radial projection of the mounting groove 9 is rectangular.

[0041] Preferably, the isolation block 8 includes a connecting hole 13 and a flow hole 14 that are interconnected, the refrigerant pipe 6 is connected to the connecting hole 13, and the flow hole 14 is connected to the tube cavity 5. By providing the connecting hole 13 and the flow hole 14 on the isolation block 8, it is convenient to install and fix the refrigerant pipe 6, and it is also convenient to realize the connection between the refrigerant pipe 6 and the tube cavity 5.

[0042] In this embodiment, the through hole 14 is an L-shaped hole, one end of the L-shaped hole is connected to the connecting hole 13, and the other end of the L-shaped hole is connected to the tube cavity 5. The cross-sectional area of ​​the connecting hole 13 is larger than the cross-sectional area of ​​the through hole 14, so that a step structure can be formed. In this way, during the installation process, the refrigerant pipe 6 can be stopped on the step structure, which can not only form a stop position for the installation of the refrigerant pipe 6, but also prevent the refrigerant pipe 6 from directly contacting the pipe wall and causing the pipe opening of the refrigerant pipe 6 to be blocked. The aperture of the connecting hole 13 is larger than the aperture of the through hole 14, so that the refrigerant can be accelerated after entering the L-shaped through hole 14, thereby increasing the flow speed of the refrigerant, and the bending structure of the L-shaped through hole 14 can make the refrigerant entering the L-shaped through hole 14 turn when entering the bending position, so that the direction of the refrigerant flowing out of the L-shaped through hole 14 is the same as the axial direction of the pipe section 4, thereby improving the flow effect of the refrigerant.

[0043] Figure 4 The figure is a schematic diagram of the flow of the refrigerant in each tube cavity 5 of the second manifold 2 when the microchannel heat exchanger of the first embodiment is used as an evaporator. The gas-liquid two-phase refrigerant enters the isolation block 8 from the refrigerant pipe 6, and is accelerated and turned by the isolation block 8 before being ejected upward into the tube cavity 5. Due to the ejection effect of the high-speed refrigerant, the pressure of the lower end of the connecting tube 7 is lower than that of the upper end, so the refrigerant entering the tube cavity 5 is divided into two parts, one part of the refrigerant enters the flat tube 3, and the other part of the refrigerant enters the connecting tube 7 from the upper end of the connecting tube 7, and then returns to the tube cavity 5 from the lower end of the connecting tube 7, forming a circulating flow. The circulating flow can make the gas phase refrigerant above the tube cavity 5 return to the bottom to mix with the two-phase refrigerant, so that the two-phase refrigerant in the tube cavity 5 is more evenly distributed, that is, the two-phase refrigerant entering each flat tube 3 is more evenly distributed, thereby improving the performance of the heat exchanger.

[0044] See also Figures 7 to 11 As shown, according to the second embodiment of the present application, it is basically the same as the first embodiment, except that, in the present embodiment, the isolation structure includes a sealing plate 15 and a throttle plate 16, and a throttling hole 17 is provided on the throttle plate 16. A guide cavity 18 is formed between the sealing plate 15 and the throttle plate 16, and the refrigerant connecting pipe 6 is connected to the guide cavity 18, and the guide cavity 18 is connected to the pipe cavity 5 through the throttle plate 16, and the guide cavity 18 is separated from the adjacent pipe section 4 by the sealing plate 15.

[0045] In this embodiment, there are N throttle plates 16, each of which is provided with a throttle hole 17, which can accelerate the refrigerant after entering the tube cavity 5 from the guide cavity 18 of the second manifold 2, thereby improving the refrigerant injection effect and further improving the uniform distribution effect of the refrigerant. The sealing plate 15 is a non-porous structure, which serves to separate two adjacent tube sections 4.

[0046] The cross-sectional structures of the sealing plate 15 and the throttle plate 16 are substantially the same as the cross-sectional structure of the isolation block 8 , and are both a combination of two semicircles of different diameters, thereby facilitating the sealing connection and fixation between the second manifolds 2 .

[0047] The second manifold 2 is provided with a mounting groove 9 , and the sealing plate 15 and the throttle plate 16 are both embedded in the mounting groove 9 .

[0048] Fig. 9 The figure is a schematic diagram of the flow of the refrigerant in each tube cavity 5 and the flow guide cavity 18 of the second manifold 2 when the microchannel heat exchanger of the second embodiment is used as an evaporator. The gas-liquid two-phase refrigerant enters the flow guide cavity 18 from the refrigerant pipe 6, is accelerated through the throttle hole 17, and then sprays upward into the tube cavity 5. Due to the injection effect of the high-speed refrigerant, the pressure of the lower end of the connecting tube 7 is lower than that of the upper end, so the refrigerant entering the tube cavity 5 is divided into two parts, one part of the refrigerant enters the flat tube 3, and the other part of the refrigerant enters the connecting tube 7 from the upper end of the connecting tube 7, and then returns to the tube cavity 5 from the lower end of the connecting tube 7, forming a circulating flow. The circulating flow can make the gas phase refrigerant above the tube cavity 5 return to the bottom to mix with the two-phase refrigerant, so that the two-phase refrigerant in the tube cavity 5 is more evenly distributed, that is, the two-phase refrigerant entering each flat tube 3 is more evenly distributed, thereby improving the performance of the heat exchanger.

[0049] The microchannel heat exchanger can be a single-row heat exchanger, a double-row heat exchanger or a multi-row heat exchanger, which can be selected according to needs.

[0050] See also Fig.13 As shown, according to an embodiment of the present application, the heat pump system includes a microchannel heat exchanger 19, and the microchannel heat exchanger 19 is the microchannel heat exchanger mentioned above.

[0051] The heat pump system also includes a compressor 20, a first heat exchanger 21, a throttling device 22 and a diverter 23 which are connected in sequence. The diverter 23 includes a plurality of diverter interfaces which are connected to the refrigerant pipe 6 in a one-to-one correspondence.

[0052] A four-way valve 24 is also provided at the exhaust end of the compressor 20 .

[0053] When the microchannel heat exchanger is used as a condenser, a and b of the four-way valve 24 are connected, c and d are connected, and the refrigerant discharged from the compressor 20 passes through the four-way valve 24, and then enters the microchannel heat exchanger 19 from the connecting pipe of the first collecting pipe 1 for condensation and heat release, and then flows out through N refrigerant connecting pipes 6, and after merging with the diverter 23, enters the throttling device 22 for throttling, and then enters the first heat exchanger 21 for evaporation and heat absorption, and then returns to the compressor 20 through the four-way valve 24 to complete the cycle.

[0054] When the microchannel heat exchanger is used as an evaporator, ac and bd of the four-way valve 24 are connected, and the refrigerant discharged from the compressor 20 enters the first heat exchanger 21 through the four-way valve 24 for condensation and heat release, and then enters the throttling device 22 for throttling, and then is split into N paths through the splitter 23, and then enters the microchannel heat exchanger 19 through N refrigerant pipes 6 for evaporation and heat absorption, and then flows out from the pipe of the first collecting pipe 1, and finally returns to the compressor 20 through the four-way valve 24 to complete the cycle.

[0055] 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.

[0056] The above are only preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application. The above are only preferred implementations of the present application. 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 application, and these improvements and variations should also be regarded as the protection scope of the present application.

Claims

1. A microchannel heat exchanger, characterized in that: The invention comprises a first header (1), a second header (2) and a flat tube (3), wherein the flat tube (3) is connected between the first header (1) and the second header (2), and a plurality of isolation structures are arranged on the second header (2) at intervals along the axial direction, wherein the isolation structures are used to separate the second header (2) into a plurality of tube sections (4) with tube cavities (5) being isolated from each other, and each of the tube sections (4) is connected to a refrigerant pipe (6); A connecting pipe (7) is arranged outside at least one of the pipe sections (4), a first end of the connecting pipe (7) is connected to a first end of the pipe section (4), and a second end of the connecting pipe (7) is connected to a second end of the pipe section (4); The isolation structure comprises an isolation block (8), the isolation block (8) comprises a connecting hole (13) and a flow hole (14) which are interconnected, the refrigerant pipe (6) is connected to the connecting hole (13), and the flow hole (14) is connected to the tube cavity (5); the cross-sectional area of ​​the connecting hole (13) is larger than the cross-sectional area of ​​the flow hole (14); or, the isolation structure comprises a sealing plate (15) and a throttle plate (16), a throttle hole (17) is provided on the throttle plate (16), a guide cavity (18) is formed between the sealing plate (15) and the throttle plate (16), the refrigerant pipe (6) is connected to the guide cavity (18), and the guide cavity (18) is connected to the tube cavity (5) through the throttle plate (16).

2. The microchannel heat exchanger according to claim 1, characterized in that: When the isolation structure comprises an isolation block (8), the structure of the isolation block (8) is compatible with the second header (2); a plurality of mounting grooves (9) are provided on the second header (2), and the isolation block (8) is arranged in the mounting grooves (9).

3. The microchannel heat exchanger according to claim 2, characterized in that: The isolation block (8) comprises a sealing portion (10) and an embedding portion (11); a stop step (12) is formed at the connection position between the sealing portion (10) and the embedding portion (11); the mounting groove (9) is a semicircular groove; the embedding portion (11) is embedded in the second manifold (2); the sealing portion (10) is embedded in the semicircular groove; the stop step (12) stops on the side walls at both ends of the semicircular groove; the sealing portion (10) and the embedding portion (11) cooperate with each other to separate the tube cavities (5) on both sides of the isolation block (8).

4. The microchannel heat exchanger according to claim 2, characterized in that: The through hole (14) is an L-shaped hole, one end of the L-shaped hole is connected to the connecting hole (13), and the other end of the L-shaped hole is connected to the tube cavity (5).

5. The microchannel heat exchanger according to claim 1, characterized in that: When the isolation structure comprises a sealing plate (15) and a throttle plate (16), the flow guide cavity (18) is separated from the adjacent pipe section (4) by the sealing plate (15).

6. The microchannel heat exchanger according to claim 5, characterized in that: The second collecting pipe (2) is provided with a mounting groove (9), and the sealing plate (15) and the throttle plate (16) are both embedded in the mounting groove (9).

7. The microchannel heat exchanger according to claim 1, characterized in that: The first collecting pipe (1) and the second collecting pipe (2) are arranged vertically, and the refrigerant connecting pipe (6) is connected to the bottom of the pipe section (4).

8. The microchannel heat exchanger according to claim 1, characterized in that: The microchannel heat exchanger is a single-row heat exchanger, a double-row heat exchanger or a multi-row heat exchanger.

9. A heat pump system, comprising a microchannel heat exchanger (19), characterized in that: The microchannel heat exchanger (19) is the microchannel heat exchanger according to any one of claims 1 to 8.

10. The heat pump system according to claim 9, characterized in that: The heat pump system also includes a compressor (20), a first heat exchanger (21), a throttling device (22) and a diverter (23) connected in sequence, and the diverter (23) includes a plurality of diverter interfaces, and the diverter interfaces are connected to the refrigerant pipes (6) in a one-to-one correspondence.

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