A microchannel heat exchanger

Abstract

This invention discloses a microchannel heat exchanger, relating to the field of heat exchanger technology. The microchannel heat exchanger includes a first manifold, a second manifold, and multiple connecting pipes. The multiple connecting pipes are arranged in parallel at intervals and are all connected between the first and second manifolds. The first manifold, the second manifold, and the multiple connecting pipes together form a heat exchange channel for refrigerant flow. A first baffle is provided inside the first manifold to divide it into a first collecting section and a second collecting section. The first collecting section is located below the second collecting section and has an inlet communicating with the heat exchange channel. A guide pipe extends from the bottom of the second collecting section and communicates with the inlet. The microchannel heat exchanger provided by this invention can realize the reflux of retained liquid refrigerant, increase the refrigerant inflow rate, improve the uniformity of refrigerant flow and distribution, improve heat exchange efficiency, and ensure heat exchange effect.

Description

Technical Field

[0001] This invention relates to the field of heat exchanger technology, and more specifically, to a microchannel heat exchanger. Background Technology

[0002] In refrigerant heat exchangers, due to the significant differences in physical properties such as density and viscosity between gaseous and liquid refrigerants, and the fact that the density of liquid refrigerant is much greater than that of gaseous refrigerant, liquid refrigerant tends to deposit at the bottom of the flow channel and become stagnant under the combined effects of inertial force and gravity. This affects the uniformity of refrigerant flow and distribution, thereby reducing heat exchange efficiency. Furthermore, it can directly lead to the inability of that portion of liquid refrigerant to continue participating in heat exchange, resulting in severe overheating in some flow paths due to insufficient liquid refrigerant, thus affecting the heat exchange effect.

[0003] Therefore, designing and manufacturing a microchannel heat exchanger that can improve the uniformity of refrigerant flow and distribution is particularly important in heat exchanger production. Summary of the Invention

[0004] The purpose of this invention is to provide a microchannel heat exchanger that can achieve the reflux of retained liquid refrigerant, increase the refrigerant inflow rate, improve the uniformity of refrigerant flow and distribution, improve heat exchange efficiency, and ensure heat exchange effect.

[0005] The present invention is achieved by the following technical solution.

[0006] A microchannel heat exchanger includes a first manifold, a second manifold, and multiple connecting pipes. The multiple connecting pipes are arranged in parallel and spaced apart, and are all connected between the first manifold and the second manifold. The first manifold, the second manifold, and the multiple connecting pipes together form a heat exchange channel for the flow of refrigerant. A first baffle is provided inside the first manifold to divide the first manifold into a first collecting section and a second collecting section. The first collecting section is located below the second collecting section and has an inlet that communicates with the heat exchange channel. A guide pipe extends from the bottom of the second collecting section and communicates with the inlet. The guide pipe is used to guide the liquid refrigerant deposited at the bottom of the second collecting section to the inlet.

[0007] Optionally, the inner diameter of the drainage tube and the diameter of the inlet satisfy the following relationship: d≤D / 5; where d is the inner diameter of the drainage tube and D is the diameter of the inlet.

[0008] Optionally, the drainage tube is located on the side of the first manifold away from the second manifold, and the inlet end of the drainage tube is 0-3mm higher than the first partition.

[0009] Optionally, the outer wall of the first manifold is provided with a first connector, and the first connector is provided with a first through hole communicating with the inlet;

[0010] The drainage tube and the first manifold are integrally formed, and the first connector is fixedly connected to both the drainage tube and the first manifold; or, the drainage tube and the first connector are integrally formed, and the first manifold is fixedly connected to both the drainage tube and the first connector; or, the first connector and the first manifold are integrally formed, and the drainage tube is fixedly connected to both the first connector and the first manifold; or, the drainage tube, the first manifold, and the first connector are all separately provided and fixedly connected to each other; or, the drainage tube, the first manifold, and the first connector are integrally formed.

[0011] Optionally, the microchannel heat exchanger also includes a first liquid pump and a first liquid extraction pipe. The first collection section is also provided with a first liquid outlet, which is located at the bottom of the first collection section and below the inlet. One end of the first liquid pump is connected to the first liquid outlet, and the other end is connected to the inlet through the first liquid extraction pipe.

[0012] Optionally, a second baffle is provided inside the second manifold to divide the second manifold into a third manifold section and a fourth manifold section. The first baffle and the second baffle are staggered in the height direction of the microchannel heat exchanger. The third manifold section is located below the fourth manifold section, and the fourth manifold section has an outlet that communicates with the heat exchange channel.

[0013] Optionally, the microchannel heat exchanger also includes a second liquid pump and a second liquid extraction pipe. A second liquid outlet is provided at the bottom of the third collection section. One end of the second liquid pump is connected to the second liquid outlet, and the other end is connected to the inlet through the second liquid extraction pipe.

[0014] Optionally, the microchannel heat exchanger also includes a third liquid pump and a third liquid extraction pipe. The fourth collection section is also provided with a third liquid outlet, which is located at the bottom of the fourth collection section and below the outlet. One end of the third liquid pump is connected to the third liquid outlet, and the other end is connected to the inlet through the third liquid extraction pipe.

[0015] Optionally, there are multiple first baffles and multiple second baffles. Multiple first baffles divide the first manifold into a first manifold section and multiple second manifold sections, and multiple second baffles divide the second manifold into a fourth manifold section and multiple third manifold sections.

[0016] Optionally, the microchannel heat exchanger also includes multiple fins, which are wavy and each fin is disposed between two adjacent connecting tubes.

[0017] The microchannel heat exchanger provided by this invention has the following beneficial effects:

[0018] The microchannel heat exchanger provided by this invention comprises multiple parallel and spaced connecting pipes, all connected between a first manifold and a second manifold. The first manifold, the second manifold, and the multiple connecting pipes together form a heat exchange channel for refrigerant flow. A first baffle is installed inside the first manifold to divide it into a first collecting section and a second collecting section. The first collecting section is located below the second collecting section and has an inlet communicating with the heat exchange channel. A guide pipe extends from the bottom of the second collecting section, communicating with the inlet, and is used to guide the liquid refrigerant deposited at the bottom of the second collecting section to the inlet. Compared with the prior art, the microchannel heat exchanger provided by this invention, due to the use of a guide pipe connecting the bottom of the second collecting section and the inlet, can achieve the reflux of retained liquid refrigerant, increase the refrigerant inflow rate, improve the uniformity of refrigerant flow and distribution, improve heat exchange efficiency, and ensure heat exchange effect. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of the microchannel heat exchanger provided in the first embodiment of the present invention;

[0021] Figure 2 This is a cross-sectional view of the microchannel heat exchanger provided in the first embodiment of the present invention;

[0022] Figure 3 This is a partial cross-sectional view of the microchannel heat exchanger provided in the first embodiment of the present invention;

[0023] Figure 4 This is a flow velocity model diagram of the refrigerant flowing in the inlet of the microchannel heat exchanger provided in the first embodiment of the present invention;

[0024] Figure 5 A mathematical model diagram of the drainage tube and the inlet valve in the microchannel heat exchanger provided in the first embodiment of the present invention;

[0025] Figure 6 This is a schematic diagram of the structure of a microchannel heat exchanger provided in the second embodiment of the present invention.

[0026] Icons: 100-Microchannel heat exchanger; 110-First manifold; 111-First baffle; 112-First manifold section; 113-Second manifold section; 114-First connector; 115-Inlet; 116-First drain port; 117-Drain pipe; 118-First through hole; 120-Second manifold; 121-Second baffle; 122-Third manifold section; 123-Fourth manifold section; 124-Second connector; 125-Outlet; 126-Second through hole; 130-Connecting pipe; 140-End cap; 150-Heat exchange channel; 160-Ventilation cavity; 170-Fin; 180-First liquid pump; 190-First extraction pipe. Detailed Implementation

[0027] 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 some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of the 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. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0029] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0030] In the description of this invention, it should be noted that the terms "inner," "outer," "upper," "lower," "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use. They are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In addition, the terms "first," "second," "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0031] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "connected," "installed," and "connected" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0032] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, features in the following embodiments can be combined with each other.

[0033] First Embodiment

[0034] Please refer to the reference. Figures 1 to 3 ( Figure 2 The hollow arrows in the diagram indicate the direction of refrigerant flow. This embodiment of the invention provides a microchannel heat exchanger 100 for heat exchange. It enables the recirculation of retained liquid refrigerant, increases the refrigerant inflow rate, improves the uniformity of refrigerant flow and distribution, enhances heat exchange efficiency, and ensures effective heat exchange.

[0035] The microchannel heat exchanger 100 includes a first manifold 110, a second manifold 120, and multiple connecting pipes 130. The first manifold 110 and the second manifold 120 are arranged parallel to each other and spaced apart. Both ends of the first manifold 110 and the second manifold 120 are sealed with end caps 140 to prevent refrigerant leakage. The multiple connecting pipes 130 are arranged parallel to each other and spaced apart, connecting between the first manifold 110 and the second manifold 120. The connecting pipes 130 are perpendicular to the first manifold 110. The first manifold 110, the second manifold 120, and the multiple connecting pipes 130 together form a heat exchange channel 150 for refrigerant flow; that is, the refrigerant in the first manifold 110 can flow to the second manifold 120 through the connecting pipes 130, and the refrigerant in the second manifold 120 can flow to the first manifold 110 through the connecting pipes 130. Specifically, there is a ventilation cavity 160 between two adjacent connecting pipes 130, and multiple connecting pipes 130 together form multiple ventilation cavities 160. The ventilation cavity 160 is used to allow air to pass through. In this way, when the air blows through the microchannel heat exchanger 100, the refrigerant in the heat exchange channel 150 can exchange heat with the air to raise or lower the air temperature, thereby realizing the heat exchange function of the microchannel heat exchanger 100.

[0036] Furthermore, the microchannel heat exchanger 100 is placed vertically, with the first manifold 110 and the second manifold 120 extending vertically and the connecting pipe 130 extending horizontally. A first baffle 111 is provided inside the first manifold 110 to divide it into a first manifold section 112 and a second manifold section 113. The first manifold section 112 is located below the second manifold section 113. The first manifold section 112 has an inlet 115 communicating with the heat exchange channel 150. The refrigerant entering the first manifold section 112 from the inlet 115 first flows through a portion of the connecting pipe 130 to the second manifold 120, and then through another portion of the connecting pipe 130 to the second manifold section 113. During this process, because the first manifold 110 extends vertically, some liquid refrigerant will deposit at the bottom of the second manifold section 113 (i.e., on the first baffle 111) and become stagnant, affecting the heat exchange effect. Specifically, a drainage pipe 117 is provided at the bottom end of the second collection section 113. The drainage pipe 117 is connected to the inlet 115. The drainage pipe 117 is used to guide the liquid refrigerant deposited at the bottom of the second collection section 113 to the inlet 115, so as to realize the return of the retained liquid refrigerant, increase the refrigerant inflow, improve the uniformity of refrigerant flow and distribution, improve heat exchange efficiency, and ensure heat exchange effect.

[0037] Preferably, the outer wall of the first manifold 110 is provided with a first connector 114, and the first connector 114 is provided with a first through hole 118 communicating with the inlet 115. The inlet 115 and the first through hole 118 are directly connected. The drain pipe 117 passes through the first connector 114 and communicates with the first through hole 118, thereby communicating with the inlet 115. Specifically, the first connector 114 is used to connect with an external pipeline to facilitate the introduction of external gas-liquid two-phase refrigerant.

[0038] In an optional embodiment, the drainage tube 117 is integrally formed with the first manifold 110, and the first connector 114 is set separately. In this case, the first connector 114 is fixedly connected to both the drainage tube 117 and the first manifold 110.

[0039] In an optional embodiment, the drainage tube 117 is integrally formed with the first connector 114, and the first manifold 110 is provided separately. In this case, the first manifold 110 is fixedly connected to both the drainage tube 117 and the first connector 114. In this case, the drainage tube 117 can be a flow channel inside the first connector 114, or it can extend outside the first connector 114.

[0040] In an optional embodiment, the first connector 114 is integrally formed with the first manifold 110, and the drainage pipe 117 is set separately. In this case, the drainage pipe 117 is fixedly connected to both the first connector 114 and the first manifold 110.

[0041] In an optional embodiment, the drainage tube 117, the first collecting tube 110, and the first connector 114 are all separately provided and fixedly connected to each other.

[0042] In an optional embodiment, the drainage tube 117, the first manifold 110, and the first connector 114 are integrally formed.

[0043] It should be noted that one end of the drain pipe 117 is connected to the bottom of the second manifold section 113, and the other end is connected to the inlet 115. Since the bottom of the second manifold section 113 is higher than the inlet 115, and the refrigerant flow rate at the inlet 115 is larger, under the combined action of gravity and the pressure difference between the two ends of the drain pipe 117, the liquid refrigerant deposited at the bottom of the second manifold section 113 will flow into the inlet 115 along the drain pipe 117, mix with the gas-liquid two-phase refrigerant introduced at the inlet 115, and then enter the first manifold section 112 to realize the reflux function of retaining liquid refrigerant and improve heat exchange efficiency.

[0044] Furthermore, the inner diameter of the drain pipe 117 and the diameter of the inlet 115 satisfy the following relationship: d ≤ D / 5; where d is the inner diameter of the drain pipe 117 and D is the diameter of the inlet 115. According to Bernoulli's principle, reducing the diameter of the inlet 115 allows the gas-liquid two-phase refrigerant entering at the inlet 115 to have a larger flow velocity and dynamic pressure, thereby reducing the static pressure near the connection between the drain pipe 117 and the inlet 115. This ensures that the liquid refrigerant deposited at the bottom of the second collection section 113 can flow into the inlet 115 along the drain pipe 117, preventing the gas-liquid two-phase refrigerant entering at the inlet 115 from directly flowing back from the drain pipe 117 to the second collection section 113.

[0045] Please refer to the reference. Figure 4 and Figure 5 It is worth noting that the drain pipe 117 is a circular pipe, and the inlet 115 is circular. In the steady and fully developed laminar flow inside the circular pipe, the cross-sectional velocity distribution of the refrigerant is parabolic, which satisfies the following relationship:

[0046]

[0047] In the formula, R is the radius of the inlet 115, R = D / 2; v max The refrigerant flow rate at the center of inlet 115; v r Let be the refrigerant flow velocity at a radius r with the inlet 115 as the center.

[0048] To prevent the gas-liquid two-phase refrigerant at inlet 115 from backflowing into the drain pipe 117, when the drain pipe 117 does not extend deep into inlet 115, the end of the drain pipe 117 extending into inlet 115 must be located in the low refrigerant flow velocity region within inlet 115. This requirement is based on the physical properties of the refrigerant, such as density and viscosity. That is to say, it requires (where h is the maximum depth at the intersection of drainage tube 117 and inlet 115), taking the square root of both sides of this inequality yields... According to the Pythagorean theorem, we get (D / 2)2 = (D / 2 - h) 2 +(d / 2) 2 Therefore, we can calculate that d ≤ D / 5.

[0049] Preferably, the drainage tube 117 is located on the side of the first manifold 110 away from the second manifold 120. The inlet end of the drainage tube 117 is higher than the first partition 111, and the height difference is 0-3mm. That is, the bottom of the inlet end of the drainage tube 117 can be flush with the upper surface of the first partition 111 or higher than the upper surface of the first partition 111 by up to 3mm, so as to ensure the drainage effect.

[0050] Preferably, the inner diameter of the drainage tube 117 is 3mm-8mm. A reasonable inner diameter of the drainage tube 117 can prevent backflow of the gas-liquid two-phase refrigerant at the inlet 115 while ensuring drainage efficiency, and it is also convenient for manufacturing. In this embodiment, the inner diameter of the drainage tube 117 is 5mm, but it is not limited to this. In other embodiments, the inner diameter of the drainage tube 117 can be 3mm or 5mm, and the size of the inner diameter of the drainage tube 117 is not specifically limited.

[0051] Preferably, the inner diameters of the first manifold 110 and the second manifold 120 are the same, ranging from 12mm to 25mm. A suitable inner diameter for the first manifold 110 and the second manifold 120 can increase the flow velocity of the refrigerant within the heat exchange channel 150, thereby improving heat exchange efficiency and enhancing the heat exchange effect. In this embodiment, the inner diameters of the first manifold 110 and the second manifold 120 are both 20mm, but this is not a limitation. In other embodiments, the inner diameters of the first manifold 110 and the second manifold 120 can both be 12mm or both be 25mm; the size of the inner diameters of the first manifold 110 and the second manifold 120 is not specifically limited.

[0052] Please continue to refer to Figures 1 to 3Optionally, a second baffle 121 is provided inside the second manifold 120 to divide the second manifold 120 into a third manifold section 122 and a fourth manifold section 123. The first baffle 111 and the second baffle 121 are offset in the height direction of the microchannel heat exchanger 100. The third manifold section 122 is located below the fourth manifold section 123. The fourth manifold section 123 has an outlet 125 that communicates with the heat exchange channel 150. The refrigerant entering the first manifold section 112 from the inlet 115 first flows to the third manifold section 122 through a part of the connecting pipe 130, then flows to the second manifold section 113 through another part of the connecting pipe 130, and then flows to the fourth manifold section 123 through yet another part of the connecting pipe 130, and finally flows out from the outlet 125.

[0053] Preferably, the outer wall of the second manifold 120 is provided with a second connector 124, and the second connector 124 is provided with a second through hole 126 communicating with the outlet 125. The outlet 125 and the second through hole 126 are directly connected. Specifically, the second connector 124 is used to connect with an external pipe to facilitate the outflow of refrigerant.

[0054] In this embodiment, there is one first baffle 111 and one second baffle 121. The first baffle 111 divides the first manifold 110 into a first manifold section 112 and a second manifold section 113, and the second baffle 121 divides the second manifold 120 into a fourth manifold section 123 and a third manifold section 122. Correspondingly, there is one drain pipe 117, which is connected between the bottom end of the second manifold section 113 and the inlet 115.

[0055] However, this is not the only option. In other embodiments, there may be multiple first baffles 111 and multiple second baffles 121. Multiple first baffles 111 divide the first manifold 110 into a first manifold section 112 and multiple second manifold sections 113. Multiple second baffles 121 divide the second manifold 120 into a fourth manifold section 123 and multiple third manifold sections 122. In this case, there may be multiple drainage pipes 117. Each drainage pipe 117 is connected between the inlet 115 and the bottom end of a second manifold section 113. Specifically, if there are two first baffles 111 and two second baffles 121, the two first baffles 111 divide the first manifold 110 into a first manifold section 112 and two second manifold sections 113, and the two second baffles 121 divide the second manifold 120 into a fourth manifold section 123 and two third manifold sections 122, then there are two drain pipes 117, and each drain pipe 117 is connected between the inlet 115 and the bottom end of a second manifold section 113.

[0056] Preferably, the microchannel heat exchanger 100 further includes multiple fins 170. The fins 170 are wavy, and each fin 170 is disposed between two adjacent connecting pipes 130, that is, the fins 170 are disposed in the ventilation cavity 160. When the air passes through the ventilation cavity 160, it will simultaneously brush over the fins 170. The fins 170 are used to increase the heat exchange area of ​​the air, thereby improving the heat exchange efficiency of the air and enhancing the heat exchange effect.

[0057] In this embodiment, the connecting pipe 130 is a flat pipe to increase the cross-sectional area of ​​the ventilation cavity 160, thereby increasing the ventilation volume and heat exchange efficiency. Specifically, the fins 170 are welded and fixed between two adjacent connecting pipes 130 to ensure the structural strength of the microchannel heat exchanger 100 and prevent the fins 170 from accidentally falling off.

[0058] The microchannel heat exchanger 100 provided in this embodiment of the invention has multiple connecting pipes 130 arranged in parallel and spaced apart, all connected between a first manifold 110 and a second manifold 120. The first manifold 110, the second manifold 120 and the multiple connecting pipes 130 together form a heat exchange channel 150 for refrigerant flow. A first baffle 111 is provided inside the first manifold 110 to divide the first manifold 110 into a first manifold section 112 and a second manifold section 113. The first manifold section 112 is located below the second manifold section 113 and has an inlet 115 communicating with the heat exchange channel 150. A guide pipe 117 extends from the bottom end of the second manifold section 113 and communicates with the inlet 115. The guide pipe 117 is used to guide the liquid refrigerant deposited at the bottom of the second manifold section 113 to the inlet 115. Compared with the prior art, the microchannel heat exchanger 100 provided by the present invention uses a flow guide pipe 117 connected between the bottom end of the second flow section 113 and the inlet 115, which enables the return of the retained liquid refrigerant, increases the flow rate of the refrigerant, improves the uniformity of the refrigerant flow and distribution, improves the heat exchange efficiency, and ensures the heat exchange effect.

[0059] Second Embodiment

[0060] Please refer to Figure 6 This embodiment of the invention provides a microchannel heat exchanger 100. Compared with the first embodiment, the difference in this embodiment is that the microchannel heat exchanger 100 also includes a liquid pump and a liquid extraction pipe.

[0061] In this embodiment, the microchannel heat exchanger 100 further includes a first liquid pump 180 and a first liquid extraction pipe 190. The first collection section 112 is also provided with a first drain port 116, which is located at the bottom end of the first collection section 112 and below the inlet 115. One end of the first liquid pump 180 is connected to the first drain port 116, and the other end is connected to the inlet 115 through the first liquid extraction pipe 190. Since the first manifold 110 extends vertically, some liquid refrigerant will be deposited at the bottom of the first manifold section 112 and become stagnant. Since the first drain port 116 is located below the inlet 115, the liquid refrigerant deposited at the bottom of the first manifold section 112 cannot be returned to the inlet 115 by the drainage pipe 117. Therefore, in this embodiment, the liquid refrigerant deposited at the bottom of the first manifold section 112 is extracted by the first liquid pump 180 and sent to the inlet 115, which can also achieve the function of returning the stagnant liquid refrigerant, further increasing the refrigerant inflow, improving the uniformity of refrigerant flow and distribution, improving heat exchange efficiency, and ensuring heat exchange effect.

[0062] Preferably, the microchannel heat exchanger 100 further includes a second liquid pump and a second liquid extraction pipe. A second drain port is provided at the bottom of the third manifold 122. One end of the second liquid pump is connected to the second drain port, and the other end is connected to the inlet 115 via the second liquid extraction pipe. Since the second manifold 120 extends vertically, some liquid refrigerant will deposit at the bottom of the third manifold 122 and become stagnant. Because the first manifold 110 is far from the second manifold 120, the liquid refrigerant deposited at the bottom of the third manifold 122 cannot flow back to the inlet 115 through the drainage pipe 117. Therefore, by using the second liquid pump to extract the liquid refrigerant deposited at the bottom of the third manifold 122 and send it into the inlet 115, the function of returning the stagnant liquid refrigerant can also be achieved, further improving heat exchange efficiency and ensuring heat exchange effect.

[0063] Preferably, the microchannel heat exchanger 100 further includes a third liquid pump and a third liquid extraction pipe. The fourth manifold 123 also has a third liquid outlet, which is located at the bottom of the fourth manifold 123 and below the outlet 125. One end of the third liquid pump is connected to the third liquid outlet, and the other end is connected to the inlet 115 through the third liquid extraction pipe. Since the second manifold 120 extends vertically, some liquid refrigerant will be deposited at the bottom of the fourth manifold 123 and become stagnant. Since the first manifold 110 is far from the second manifold 120, the liquid refrigerant deposited at the bottom of the fourth manifold 123 cannot be returned to the inlet 115 by the drainage pipe 117. Therefore, by using the third liquid pump to extract the liquid refrigerant deposited at the bottom of the fourth manifold 123 and send it into the inlet 115, the function of returning the stagnant liquid refrigerant can also be realized, further improving the heat exchange efficiency and ensuring the heat exchange effect.

[0064] The beneficial effects of the microchannel heat exchanger 100 provided in this embodiment of the invention are the same as those in the first embodiment, and will not be repeated here.

[0065] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A microchannel heat exchanger, characterized in that, The device includes a first manifold, a second manifold, and multiple connecting pipes. The multiple connecting pipes are arranged in parallel and spaced apart, and are all connected between the first manifold and the second manifold. The first manifold, the second manifold, and the multiple connecting pipes together form a heat exchange channel for refrigerant flow. The heat exchange channel is used for refrigerant flow. A first baffle is provided inside the first manifold to divide the first manifold into a first collecting section and a second collecting section. The first collecting section is located below the second collecting section. The first collecting section has an inlet that communicates with the heat exchange channel. A drain pipe extends from the bottom of the second collecting section and communicates with the inlet. The drain pipe can drain the liquid refrigerant deposited at the bottom of the second collecting section to the inlet.

2. The microchannel heat exchanger according to claim 1, characterized in that, The inner diameter of the drainage tube and the diameter of the inlet satisfy the following relationship: d≤D / 5; In the formula, d is the inner diameter of the drainage tube, and D is the diameter of the inlet.

3. The microchannel heat exchanger according to claim 1 or 2, characterized in that, The drainage tube is located on the side of the first manifold away from the second manifold, and the inlet end of the drainage tube is 0-3mm higher than the first partition.

4. The microchannel heat exchanger according to claim 1 or 2, characterized in that, The outer wall of the first manifold is provided with a first connector, and the first connector is provided with a first through hole communicating with the inlet; The drainage tube is integrally formed with the first manifold, and the first connector is fixedly connected to both the drainage tube and the first manifold; or, the drainage tube is integrally formed with the first connector, and the first manifold is fixedly connected to both the drainage tube and the first connector; or, the first connector is integrally formed with the first manifold, and the drainage tube is fixedly connected to both the first connector and the first manifold; or, the drainage tube, the first manifold, and the first connector are all separately provided and fixedly connected to each other; or, the drainage tube, the first manifold, and the first connector are integrally formed.

5. The microchannel heat exchanger according to claim 1, characterized in that, The microchannel heat exchanger also includes a first liquid pump and a first liquid extraction pipe. The first collection section is also provided with a first liquid outlet, which is located at the bottom end of the first collection section and below the inlet. One end of the first liquid pump is connected to the first liquid outlet, and the other end is connected to the inlet through the first liquid extraction pipe.

6. The microchannel heat exchanger according to claim 1, characterized in that, The second manifold is provided with a second baffle to divide the second manifold into a third manifold section and a fourth manifold section. The first baffle and the second baffle are staggered in the height direction of the microchannel heat exchanger. The third manifold section is located below the fourth manifold section. The fourth manifold section has an outlet that communicates with the heat exchange channel.

7. The microchannel heat exchanger according to claim 6, characterized in that, The microchannel heat exchanger also includes a second liquid pump and a second liquid extraction pipe. A second liquid outlet is provided at the bottom of the third collection section. One end of the second liquid pump is connected to the second liquid outlet, and the other end is connected to the inlet through the second liquid extraction pipe.

8. The microchannel heat exchanger according to claim 6, characterized in that, The microchannel heat exchanger also includes a third liquid pump and a third liquid extraction pipe. The fourth collection section is also provided with a third liquid outlet, which is located at the bottom of the fourth collection section and below the outlet. One end of the third liquid pump is connected to the third liquid outlet, and the other end is connected to the inlet through the third liquid extraction pipe.

9. The microchannel heat exchanger according to claim 6, characterized in that, There are multiple first baffles and multiple second baffles. The multiple first baffles divide the first manifold into a first manifold section and multiple second manifold sections, and the multiple second baffles divide the second manifold into a fourth manifold section and multiple third manifold sections.

10. The microchannel heat exchanger according to claim 1, characterized in that, The microchannel heat exchanger also includes multiple fins, which are wavy, and each fin is disposed between two adjacent connecting tubes.

Images