Flat tubes and heat exchangers

Abstract

The present application provides a flat tube and a heat exchanger, each of which is provided with a microchannel. The microchannels have two ends, extending in the direction of their extension, located on the two end faces of the flat tube. The outer wall of the flat tube is provided with a connection hole that communicates with the microchannel. On the one hand, by increasing the area of ​​the hole through which refrigerant flows in the flat tube, capillary action is reduced, thereby lowering the probability of the microchannel being blocked by solder. On the other hand, by increasing the path for refrigerant to enter the microchannel, the microchannel is more difficult to completely block, and is less likely to be completely blocked by solder. The amount of refrigerant flowing in the flat tube is less likely to decrease, significantly increasing the probability that the microchannel in the flat tube will operate normally, resulting in high heat exchange efficiency and good cooling or heating effects.

Description

Technical Field

[0001] The present invention relates to the technical field of heat exchange, and in particular to a flat tube and a heat exchanger. Background Art

[0002] A microchannel heat exchanger consists of two manifolds, flat tubes connecting the two manifolds, and fins located between the flat tubes. The ends of the flat tubes are plugged into the two manifolds. The flat tubes are equipped with microchannels for the refrigerant to flow through. The operating principle is that the refrigerant enters the manifold through the inlet of one manifold, then flows through the manifold into the microchannels of the flat tubes, and then from the microchannels into the other manifold. As the refrigerant flows through the flat tubes, it exchanges heat with the outside medium, such as the air, thereby achieving cooling or heating.

[0003] Research has found that existing heat exchangers have the following shortcomings:

[0004] The heat exchange efficiency is low. Summary of the Invention

[0005] An object of the present invention is to provide a flat tube and a heat exchanger, which can improve heat exchange efficiency.

[0006] The embodiment of the present invention is achieved as follows:

[0007] In a first aspect, the present invention provides a flat tube having a microchannel. The two ends of the microchannel in the extension direction are respectively located on the two end faces of the flat tube. A connecting hole communicating with the microchannel is provided on the outer peripheral wall of the flat tube.

[0008] In an optional embodiment, a plurality of microchannels are provided, and the connecting hole connects the plurality of microchannels simultaneously.

[0009] In an optional embodiment, a plurality of microchannels are provided, a plurality of connecting holes are provided, and the plurality of connecting holes correspond one-to-one to and are connected with the plurality of microchannels.

[0010] In an optional embodiment, the outer peripheral wall includes two plate surfaces arranged in the thickness direction of the flat tube, and the connecting holes are provided on the plate surfaces.

[0011] In an optional embodiment, the connecting hole passes through both plate surfaces simultaneously.

[0012] In an optional embodiment, the flat tube has two width side surfaces in its width direction, each end surface is connected to the two width side surfaces at the same time, and the angle between the end surface and the width side surface at the connection position is an acute angle or an obtuse angle.

[0013] In an optional embodiment, the end surface is configured as an arc surface or a bent surface.

[0014] In an optional embodiment, the connecting hole is configured as a circular hole or a strip-shaped hole.

[0015] In a second aspect, the present invention provides a heat exchanger, comprising:

[0016] The flat tube of any of the preceding embodiments.

[0017] In an optional embodiment, the heat exchanger further includes a header, the header is provided with a slot, the ends of the flat tubes are inserted into the slot, and the flat tubes are welded to the header.

[0018] The beneficial effects of the embodiments of the present invention are:

[0019] In summary, this embodiment provides a flat tube, the ends of which are respectively inserted into two manifolds, and the flat tube and the two manifolds are welded together. Researchers discovered that when welding the flat tube to the manifolds, molten solder can enter the manifolds through the weld due to capillary action. The solder can flow along the flat tube's surface within the manifolds, reaching the ports of the microchannels. This can cause the solder to block some of the microchannels, preventing refrigerant from flowing through them and causing them to malfunction. This reduces the refrigerant flow rate in the flat tube, lowering the efficiency of heat exchange between the flat tube and the surrounding environment through the fins, resulting in low heat exchange efficiency and even affecting normal operation of the heat exchanger. The flat tube provided in this embodiment has connecting holes on its outer circumferential wall, which communicate with the microchannels. The provision of the connecting holes increases the flow path for refrigerant to enter the microchannels. Refrigerant can enter the microchannels not only from the ports on the flat tube's end faces but also from the connecting holes. Such a design, on the one hand, reduces the capillary phenomenon by increasing the area of ​​the holes for refrigerant circulation on the flat tubes, thereby reducing the probability of the microchannels being blocked by solder; on the other hand, since the path for the refrigerant to enter the microchannels is increased, the difficulty of completely blocking the microchannels is increased, the microchannels are not easily completely blocked by solder, and the amount of refrigerant flowing in the flat tubes is not easily reduced. The probability of the microchannels in the flat tubes being able to operate normally is greatly increased, the heat exchange efficiency is high, and the cooling or heating effect is good. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 Schematic diagram of the three-dimensional structure of a flat tube according to an embodiment of the present invention;

[0022] Figure 2A schematic structural diagram of a flat tube according to an embodiment of the present invention from one perspective;

[0023] Figure 3 A schematic structural diagram of a flat tube according to an embodiment of the present invention from another perspective;

[0024] Figure 4 This is a schematic structural diagram of a modified example of a flat tube according to an embodiment of the present invention;

[0025] Figure 5 Schematic diagram of the structure of another modified example of the flat tube of the embodiment of the present invention;

[0026] Figure 6 This is a schematic structural diagram of another modified example of the flat tube according to the embodiment of the present invention;

[0027] Figure 7 Schematic diagram for comparison;

[0028] Figure 8 Schematic diagram of the structure of a heat exchanger according to an embodiment of the present invention;

[0029] Figure 9 Schematic diagram of the structure of a modified example of the heat exchanger according to the embodiment of the present invention.

[0030] icon:

[0031] 001-straight end face; 100-flat tube; 110-microchannel; 120-peripheral wall; 121-first plate surface; 122-first side surface; 123-second plate surface; 124-second side surface; 130-connecting hole; 140-end face; 200-collecting pipe. DETAILED DESCRIPTION

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0033] 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 invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0034] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0035] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" and the like indicate positions or locations based on the positions shown in the accompanying drawings, or the positions or locations in which the inventive product is typically placed when in use. These terms are intended solely to facilitate the description of the present invention and to simplify the description, and are not intended to indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third," etc., are used solely to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0036] Furthermore, terms such as "horizontal" and "vertical" do not necessarily mean that a component must be absolutely horizontal or overhanging, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but rather that it can be slightly tilted.

[0037] In the description of the present invention, it should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0038] During the manufacturing process of heat exchangers such as condensers, multiple flat tubes need to be welded between two manifolds. Typically, a flat tube groove is provided on the wall of the manifold. The width of the flat tube groove is substantially equal to that of the flat tube. The ends of the flat tubes are inserted into the manifold through the flat tube groove, and the microchannels on the flat tubes are connected to the manifold. The flat tubes are then welded together at the connection points between the flat tubes and the flat tube grooves. During the welding process, due to capillary action, solder will enter the manifold through the weld and flow along the surface of the flat tubes within the manifold. The solder will flow to the ports of the microchannels, causing the solder to block some of the microchannels, which in turn prevents some of the microchannels from flowing refrigerant, meaning that some of the microchannels cannot function properly. This reduces the refrigerant flow in the flat tubes, reducing the efficiency of the flat tubes in exchanging heat with the external space and other media through the fins. This results in low heat exchange efficiency and may even affect the normal operation of the heat exchanger.

[0039] See also Figures 1-6In view of this, the designer designed a flat tube 100 that can reduce the capillary phenomenon that occurs when the flat tube 100 is welded to the collecting pipe 200. At the same time, it can also increase the flow path of the refrigerant into the microchannel 110, thereby reducing the probability of the microchannel 110 being blocked.

[0040] See also Figure 1-Figure 3 In this embodiment, the flat tube 100 is provided with a microchannel 110, and the two ends of the microchannel 110 in its extension direction are respectively located on the two end surfaces 140 of the flat tube 100; the outer peripheral wall 120 of the flat tube 100 is provided with a connecting hole 130 connected to the microchannel 110.

[0041] The flat tube 100 provided in this embodiment has a connecting hole 130 disposed on its outer peripheral wall 120. The connecting hole 130 communicates with the microchannel 110. The provision of the connecting hole 130 increases the flow path for refrigerant to enter the microchannel 110. That is, refrigerant can enter the microchannel 110 not only from the microchannel 110's port located on the end surface 140 of the flat tube 100 but also from the connecting hole 130. Such a design, on the one hand, reduces the capillary phenomenon that occurs when the flat tubes 100 and the manifold 200 are welded by increasing the area of ​​the holes for refrigerant circulation on the flat tubes 100, thereby reducing the probability of the microchannels 110 being blocked by solder. On the other hand, since the path for the refrigerant to enter the microchannels 110 is increased, the number of refrigerant inlets into the microchannels 110 increases, making it more difficult for all the refrigerant inlets into the microchannels 110 to be blocked by solder. The multiple inlets into the microchannels 110 are less likely to be blocked by solder, and the probability of the microchannels 110 in the flat tubes 100 being able to operate normally is high. The flow rate of the refrigerant flowing in the flat tubes 100 is less likely to be reduced, the heat exchange efficiency between the flat tubes 100 and the external medium is high, and the cooling or heating effect is good.

[0042] Please combine Figure 2In this embodiment, the flat tube 100 is optionally configured in a rectangular plate shape. The outer peripheral wall 120 of the flat tube 100 is the outer wall surrounding the flat tube 100 in its extension direction. Specifically, the outer peripheral wall 120 of the flat tube 100 includes a first plate surface 121, a first side surface 122, a second plate surface 123, and a second side surface 124, which are sequentially connected end to end. The first plate surface 121 and the second plate surface 123 are disposed opposite each other in the thickness direction of the flat tube 100, and the first side surface 122 and the second side surface 124 are disposed opposite each other in the width direction of the flat tube 100. The flat tube 100 also has two end surfaces 140 disposed opposite each other in its length direction. Each end surface 140 is connected to the first plate surface 121, the second plate surface 123, the first side surface 122, and the second side surface 124. Furthermore, rounded corners are provided at the junctions of the first plate surface 121, the first side surface 122, the second plate surface 123, and the second side surface 124 to enhance the structural strength of the flat tube 100 and extend its service life. This also reduces the risk of cracks during the forming process, thereby improving the yield rate of the flat tube 100. The thickness, width, and length directions of the flat tube 100 are perpendicular to each other. For example, in this embodiment, the thickness direction of the flat tube 100 is indicated by arrows ab, the width direction is indicated by arrows cd, and the length direction is indicated by arrows ef.

[0043] It should be noted that the flat tube 100 can be formed by extrusion. During the forming process, multiple microchannels 110 are directly formed within the flat tube 100. Each microchannel 110 can be a straight hole extending along the length of the flat tube 100. The two ends of each microchannel 110 are respectively located on two end surfaces 140 along the length of the flat tube 100. The multiple microchannels 110 are arranged in parallel and are evenly spaced across the width of the flat tube 100.

[0044] In addition, each microchannel 110 can be configured as a circular hole, a square hole, or an elliptical hole, etc., that is, the cross-sectional profile of each microchannel 110 can be circular, square, or elliptical, etc., which are not listed one by one in this embodiment. Among them, the cross section is a plane perpendicular to the length direction of the microchannel 110.

[0045] Please combine Figure 3 Also see Figure 5 or Figure 6Furthermore, the angle α at the connection position between each end face 140 and the first side face 122 and the second side face 124 is an obtuse angle, that is, each end face 140 is set as an outward convex surface. For example, each end face 140 is set as an outward convex arc surface or a bent surface. When the end face 140 is set as an arc surface, the angle between the end face 140 and the first side face 122 or the second side face 124 is the angle between the first side face 122 or the second side face 124 and the cross-section of the end face 140. With such a design, the width of each end face 140 gradually decreases in the direction from close to the first side face 122 to away from the first side face 122, so that each flat tube 100 can be inserted deeper into the manifold 200. It can be understood by those skilled in the art that when the size of the manifold 200 is the same as the width of the flat tube 100, the total amount of solder is certain. Compared with the existing straight end face 001 and the first side face 122 or the second side face 124 (the angle between the two is a right angle), the flat tube 100 provided in this embodiment is perpendicular to the first side face 122 or the second side face 124. Since the connection between the end face 140 and the first side face 122 or the second side face 124 in this embodiment is an obtuse angle, the distance between the connection position of the end face 140 and the first side face 122 or the second side face 124 and the microchannel 110 is increased. When the solder flows the same distance on the end face 140 under the action of capillary phenomenon, the distance between the solder and the microchannel 110 is increased, thereby reducing the probability of the microchannel 110 being blocked by solder. Please combine Figure 7 In other words, the existing straight end face 001, the end face 140 of this embodiment and the microchannel 110 at the same position form a right triangle. The distance that the solder travels from the existing straight end face 001 to the microchannel 110 is the right angle side of the right triangle, and the distance that the solder travels from the end face 140 of this embodiment to the microchannel 110 is the hypotenuse of the right triangle. The distance of the hypotenuse is preferably greater than the distance of the right angle side. In this way, when the solder travels the same distance, it is not easy for the solder to clog the port of the microchannel 110 located on the oblique surface, thereby reducing the probability of the microchannel 110 being clogged.

[0046] It should be understood that in other embodiments, the angle between the end face 140 and the first side face 122 or the second side face 124 at the connection position is an acute angle, that is, the end face 140 is concave, which can also extend the distance of the solder from the connection position to the microchannel 110 and reduce the probability of the microchannel 110 being blocked.

[0047] Please combine Figure 2-Figure 6In this embodiment, the connection hole 130 is provided on at least one of the first plate surface 121 and the second plate surface 123 of the flat tube 100. That is, the connection hole 130 can be provided only on the first plate surface 121 or the second plate surface 123 and communicate with the microchannel 110. In other words, the connection hole 130 is a blind hole with a port located on the first plate surface 121 or the second plate surface 123. In this case, refrigerant can enter the microchannel 110 from both the port of the microchannel 110 and the port of the connection hole 130. Alternatively, the connection hole 130 extends through the flat tube 100 along its thickness, with the two ports of the connection hole 130 located on the first plate surface 121 and the second plate surface 123, respectively. In other words, the connection hole 130 is a through hole with two ports located on the first plate surface 121 and the second plate surface 123, respectively. Refrigerant can enter the microchannel 110 from both the port of the microchannel 110 and the two ports of the connection hole 130.

[0048] It should be noted that the number of connection holes 130 is set to one, and the connection hole 130 is a strip-shaped hole. The connection hole 130 extends along the width direction of the flat tube 100 and is connected to multiple microchannels 110. Obviously, the connection hole 130 can be located only on the first plate surface 121 or the second plate surface 123, or can extend through the flat tube 100.

[0049] In other embodiments, a plurality of connection holes 130 are provided on the same plate surface of the flat tube 100 , and the plurality of connection holes 130 are respectively connected to the plurality of microchannels 110 .

[0050] It should be understood that the shape of the connection hole 130 can be set as needed. For example, the connection hole 130 can be a square hole, a round hole, an elliptical hole, etc.

[0051] The flat tube 100 provided in this embodiment has a connection hole 130 provided on the outer peripheral wall 120 thereof, which is connected to the microchannel 110. This increases the inlet for the refrigerant to enter the microchannel 110, thereby making it difficult to reduce the refrigerant flow rate in the flat tube 100 and the heat exchange amount, thereby improving the heat exchange efficiency.

[0052] See also Figure 8-Figure 9 This embodiment further provides a heat exchanger, comprising two manifolds 200 and the flat tubes 100 mentioned in the above embodiment. A slot is provided on the tube wall of each manifold 200, and the two ends of the flat tube 100 are respectively inserted into the corresponding slots on the two manifolds 200. There is a distance between the end surface 140 of the flat tube 100 and the inner tube wall of the manifold 200.

[0053] It should be noted that the width of the flat tube 100 is smaller than the inner diameter of the header 200 .

[0054] It should be understood that there may be multiple flat tubes 100 , and the multiple flat tubes 100 are arranged at intervals along the length direction of the header 200 .

[0055] In addition, fins are provided between adjacent flat tubes 100 to improve heat exchange efficiency. In addition, the figure only shows the matching structure of one end of the flat tube 100 and the manifold 200. The matching structure of the other end can be the same as that shown in the figure and is therefore not shown.

[0056] Those skilled in the art should understand that the heat exchanger also includes other components for achieving its basic functions, which are not listed one by one in this embodiment.

[0057] In the heat exchanger provided in this embodiment, the microchannels 110 provided inside the flat tubes 100 are not easily clogged by solder, and the flow rate of the solder flowing in the microchannels 110 is not easily reduced, thereby achieving high heat exchange efficiency.

[0058] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A flat tube used in a heat exchanger, characterized by: The flat tube is provided with a microchannel, and the two ends of the microchannel in the extension direction are respectively located on the two end surfaces of the flat tube; the outer peripheral wall of the flat tube is provided with a connecting hole connected to the microchannel; The heat exchanger further comprises a header, wherein the header is provided with a slot, the ends of the flat tubes are inserted into the slots, and the flat tubes are welded to the header; The refrigerant can enter the microchannel not only from the port of the microchannel located on the end surface of the flat tube, but also from the connecting hole.

2. The flat tube according to claim 1, characterized in that: There are multiple microchannels, and the connecting holes are connected to the multiple microchannels at the same time.

3. The flat tube according to claim 1, characterized in that: There are multiple microchannels, and there are multiple connecting holes. The multiple connecting holes correspond to and are connected with the multiple microchannels one by one.

4. The flat tube according to any one of claims 1 to 3, characterized in that: The outer peripheral wall includes two plate surfaces arranged in the thickness direction of the flat tube, and the connecting holes are provided on the plate surfaces.

5. The flat tube according to claim 4, characterized in that: The connecting hole passes through the two plate surfaces simultaneously.

6. The flat tube according to claim 1, characterized in that: The flat tube has two width side surfaces in its width direction, each of the end surfaces is connected to the two width side surfaces at the same time, and the angle between the end surface and the width side surfaces at the connection position is an acute angle or an obtuse angle.

7. The flat tube according to claim 6, characterized in that: The end surface is configured as an arc surface or a bent surface.

8. The flat tube according to claim 1, characterized in that: The connecting holes are configured as round holes or strip-shaped holes.

9. A heat exchanger, characterized in that: The heat exchanger comprises: The flat tube according to any one of claims 1 to 8.

Images